Image heating device and imaging device

Abstract

The present invention provides an image heating device and an imaging device. The image heating device includes: a first rotating member; a second rotating member, which forms a clamping portion with the first rotating member to clamp a recording material between the first rotating member and the second rotating member; a heater, which heats the clamping portion; a conductive sheet member, which is arranged to overlap with a portion of the heater; and a limiting member, which limits the relative position between the conductive sheet member and the heater. The limiting member is configured to limit the relative movement between the conductive sheet member and the heater in a first direction, but allows relative movement in a second direction perpendicular to the first direction, the first direction being a direction in which the conductive sheet member overlaps with a portion of the heater. The reinforcing area that combines the heater with the sheet member is arranged in an electrically isolated position.

Description

Technical Field

[0001] The present invention relates to an image heating device of a fixing device installed in an electrophotographic recording type image forming device (e.g., a copier, a printer), and a glossiness processing device for increasing the glossiness value of a toner image fixed on a recording material by reheating the toner image. In particular, the present invention relates to a temperature detection structure of a heater used for heat fixing in a fixing device which is an example of an image heating device. Background Art

[0002] A fixing device installed in an imaging device (e.g., a copier, a printer) as an example of the above-mentioned image heating device generally includes a film that transfers heat to a recording material and a heating resistor arranged on a ceramic substrate. In addition, the fixing device includes a heater in contact with the inner surface of the film, and a roller that forms a clamping portion with the heater across the film. In the heater, the heating area is divided into a plurality of sub-areas in the longitudinal direction of the heater, and the temperature of each sub-area can be adjusted independently. In such a fixing device, a configuration has been proposed in which a thermistor (temperature detection element) is formed for each heating area and the temperature is detected for each heating area (Japanese Patent Application Publication No. 2017-054071). Summary of the invention

[0003] In the above-mentioned structure according to Japanese Patent Application Publication No. 2017-054071, each temperature detection element has an electrical contact at the edge of the heater via a conductor and is connected to the control substrate through an electric wire. For the electric wire, a flexible sheet such as a flexible printed circuit (FPC) or a flexible flat cable (FFC) is used. The temperature detection element and the heater are connected by welding the electric contacts. The use of a flexible sheet can improve the assembly of the fixing device by making the wiring of the electric wire easier. The connection portion where the flexible sheet is welded to the electric contact on the edge of the heater is usually reinforced by a tape or an adhesive because the connection portion has a strong resistance to the force in the shear direction, but is susceptible to the force in the peeling direction. However, the heater including the heating element reaches a high temperature and the tape or adhesive to be used must be resistant to high temperatures, so there is a concern about increased costs.

[0004] An object of the present invention is to provide a configuration capable of reinforcing bonding of a thermistor electrode of a heater to a flexible sheet and suppressing solder peeling and electrode peeling without using a tape and an adhesive.

[0005] In order to achieve the above-mentioned object, an image heating device for heating an image formed on a recording material according to the present invention comprises:

[0006] a first rotating member;

[0007] a second rotating member that contacts the first rotating member and forms a nip portion with the first rotating member to nip the recording material between the first rotating member and the second rotating member;

[0008] a heater that heats the clamping portion;

[0009] a conductive sheet member electrically connected to the heater by being arranged to overlap a portion of the heater; and

[0010] a restricting member that restricts a relative position between the conductive sheet member and the heater while maintaining an electrical connection state between the conductive sheet member and the heater;

[0011] The limiting member is configured to limit relative movement between the conductive sheet member and the heater in a first direction but allow relative movement in a second direction perpendicular to the first direction, the first direction being a direction in which the conductive sheet member overlaps a portion of the heater.

[0012] In addition, in order to achieve the above-mentioned object, an image heating device for heating an image formed on a recording material according to the present invention comprises:

[0013] a first rotating member;

[0014] a second rotating member that contacts the first rotating member and forms a nip portion with the first rotating member to nip the recording material between the first rotating member and the second rotating member;

[0015] a heater that heats the clamping portion; and

[0016] a conductive sheet member electrically connected to the heater by being arranged to overlap a portion of the heater;

[0017] wherein the conductive sheet member includes a sheet member side reinforcement area, the sheet member side reinforcement area is arranged in a joining portion with respect to the heater located inside an electrical connection portion with respect to the heater, the electrical connection portion being arranged on an edge side of the conductive sheet member,

[0018] wherein the heater includes a heater-side reinforcement region arranged in the bonding portion at a position facing the sheet member-side reinforcement region,

[0019] Among them, the sheet member side reinforcement region and the heater side reinforcement region facing each other are bonded.

[0020] In order to achieve the above object, the imaging device according to the present invention comprises:

[0021] an image forming section which forms an image on a recording material; and

[0022] a fixing section that fixes the image formed by the image forming section onto the recording material;

[0023] Among them, the fixing part is the above-mentioned image heating device.

[0024] As described above, according to the present invention, the peeling resistance of the flexible sheet welded to the thermistor electrode of the heater can be enhanced without using a tape or an adhesive.

[0025] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view showing the overall configuration of an imaging device to which the present invention can be applied;

[0027] Figure 2 is a sectional view showing the configuration of a fixing nip according to Embodiments 1, 2, and 3 of the present invention;

[0028] Figure 3A 3E are diagrams showing the construction of the heater;

[0029] Figure 4A and 4B 1 is a diagram showing a protective structure of a contact portion of a thermistor according to Embodiments 1 and 3 of the present invention;

[0030] Figure 5 1 is a diagram showing a protective structure of a contact portion of a thermistor according to Embodiments 1 and 3 of the present invention;

[0031] Fig. 6A and 6B 1 is a diagram showing a protective structure of a contact portion of a thermistor according to Embodiments 2 and 3 of the present invention;

[0032] Figure 7 is a diagram showing the configuration of contacts of a heating electrode according to Embodiments 2 and 3 of the present invention;

[0033] Figure 8 is a diagram showing a housing member holding a contact member according to Embodiments 2 and 3 of the present invention;

[0034] Fig. 9 is a diagram showing a protective structure of a contact portion of a thermistor according to Embodiments 2 and 3 of the present invention; and

[0035] 10 to 10E are diagrams showing the configuration of a heater according to Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0036] Hereinafter, a description of various embodiments (examples) of the present invention will be given with reference to the accompanying drawings. However, the size, material, shape, relative arrangement, etc. of the constituent elements described in the various embodiments may be appropriately changed according to the configuration of the device to which the present invention is applied, various conditions, etc. Therefore, the size, material, shape, relative arrangement, etc. of the constituent elements described in the various embodiments are not intended to limit the scope of the present invention to the following embodiments.

[0037] Example 1

[0038] Overview of imaging devices

[0039] First, an image forming apparatus to which the present invention is applicable will be described. Figure 1 1 is a longitudinal sectional view showing a general configuration of a printer 1 provided with a fixing device, which is an example of an image heating device according to the present invention. A drawer-type box 2 is stored in a lower portion of the printer 1. A manual feed portion 3 is arranged on the right side of the printer 1. Recording materials P can be loaded and stored in the box 2 and the manual feed portion 3, respectively, and the recording materials P are separated and fed to the registration roller 4 sheet by sheet. The printer 1 includes an image forming portion 5 in which image forming stations 5Y, 5M, 5C, and 5K corresponding to yellow, magenta, cyan, and black, respectively, are arranged in a row in the lateral direction.

[0040] In the image forming section 5, photosensitive drums 6Y, 6M, 6C, and 6K (hereinafter referred to as photosensitive drums 6) as image bearing members, and charging devices 7Y, 7M, 7C, and 7K for uniformly charging the surfaces of the photosensitive drums 6 are arranged. Also arranged are a scanner unit 8 for emitting laser beams according to image information and forming electrostatic latent images on the photosensitive drums 6; and developing devices 9Y, 9M, 9C, and 9K for attaching toners to the electrostatic latent images to develop the electrostatic latent images into toner images. In addition, primary transfer sections 11Y, 11M, 11C, and 11K (hereinafter referred to as primary transfer sections 11) for transferring the toner images of each photosensitive drum 6 onto the electrostatic transfer belt 10 are arranged. The respective toner images on the transfer belt 10 transferred by the respective primary transfer sections 11 are transferred to the recording material P by the secondary transfer section 12. Then, when the transferred image passes through the fixing device 100 as a fixing portion (image heating portion), the transferred image is fixed to the recording material P by pressure and heat from the heating unit 101 and the pressure roller 102, which contacts the heating unit 101 with pressure. Then, the conveying path is switched by the double-sided flapper 13, and the recording material P is conveyed to the discharge roller pair 14 or the return roller pair 15. If the recording material P is conveyed to the return roller pair 15 side, the recording material P is reversed by the return roller pair 15, and passes through the registration roller 4, the secondary transfer portion 12, and the fixing device 100 again, and then is conveyed to the discharge roller pair 14 side, thereby performing double-sided printing. Finally, the recording material P passes through the discharge roller pair 14 and is discharged to the recording material P loading portion 16.

[0041] As the image forming apparatus, a full-color laser beam printer including a plurality of photosensitive drums 6 has been described above, but the present invention can also be applied to a fixing device included in a monochrome copying machine or printer including one photosensitive drum 6 .

[0042] Fixing device

[0043] Next, we will refer to Figure 2 A fixing device to which the present invention is applicable is described. Figure 21 is a cross-sectional view of a fixing nip formed by a heating unit 101 and a pressure roller 102. The heating unit 101 includes: a tubular film 103 as a first rotating member; a heater 200 arranged on the inner side of the tubular film 103, a heater holding member 105 holding the heater 200; and a metal support member 104. The heater 200, the heater holding member 105, and the support member 104 constitute a heater unit 111. The heater 200 has a heating element on the side opposite to the film 103 (on the rear surface) with respect to the base layer 201, the heating element includes a first heating resistor 202a and a second heating resistor 202b, and transfers heat to the tubular film 103 through the base layer 201 and the sliding surface layer 207. The pressure roller 102 as a second rotating member has a core bar made of metal and an elastic layer made of silicone rubber or the like, and forms a fixing nip with its rubber layer. The heater holding member 105 is pressed in a direction toward the pressure roller 102 via the support member 104 by a pressure unit (not shown). In other words, the heating unit 101 is pressed toward the pressure roller 102 so that the heating unit 101 and the pressure roller 102 form a fixing nip that holds the conveyed recording material P. The pressure roller 102 is rotationally driven in the rotation direction R by a driving unit (not shown), and the tubular film 103 is driven in the rotation direction R as the pressure roller 102 rotates.

[0044] Heater

[0045] Reference Figure 3A 3E to 3E describe the features of the heater to which the present invention is applied. Figure 3A 2 is a cross-sectional view of the heater 200 in the shorter direction (the direction perpendicular to the conveying direction of the recording material P). The heater 200 is heated by the first heating resistor 202a and the second heating resistor 202b arranged on the energized layer of the ceramic substrate 201, and the longitudinal direction of the ceramic substrate is the direction perpendicular to the conveying direction of the recording material P. In the energized layer, the first conductor 203 and the second conductor 204 are arranged along the longitudinal direction of the heater. The first conductor 203 is branched into the upstream side and the downstream side in the conveying direction of the recording material P, namely, the conductor 203a and the conductor 203b, respectively. The second conductor 204 is arranged between the first heating resistor 202a and the second heating resistor 202b.

[0046] On the rear surface of the heater 200, an insulating protective layer 206 is arranged to cover the two heating resistors 202a, 202b and the conductors 203, 204. On the sliding surface side where the heater 200 slides relative to the film 103, a sliding surface layer 207 coated with a material having good sliding properties (e.g., glass, polyimide) is arranged.

[0047] Figure 3B, 3C and 3D are plan views of each layer of the heater 200. In the heater 200, a plurality of heating blocks are arranged along the longitudinal direction of the heater 200, each of which includes a second conductor 204, a first heating resistor 202a and a second heating resistor 202b arranged in an energized layer. In the case of the heater 200 of Example 1, a total of five heating blocks are arranged along the longitudinal direction of the heater 200. The first heating block 202-1 is composed of the following components: a first heating resistor 202-1a and a second heating resistor 202-1b formed symmetrically in the shorter direction of the heater 200; a portion 204-1 of the second conductor 204; and an electrode 205-1 mentioned later. Similarly, the second heating block 202-2 is composed of the following components: a first heating resistor 202-2a and a second heating resistor 202-2b; a portion 204-2 of the second conductor 204; and an electrode 205-2 mentioned later. The third heating block 202-3 is composed of the following components: a first heating resistor 202-3a and a second heating resistor 202-3b; a portion 204-3 of the second conductor 204; and an electrode 205-3 mentioned later. The fourth heating block 202-4 is composed of the following components: a first heating resistor 202-4a and a second heating resistor 202-4b; a portion 204-4 of the second conductor 204; and an electrode 205-4 mentioned later. The fifth heating block 202-5 is composed of the following components: a first heating resistor 202-5a and a second heating resistor 202-5b; a portion 204-5 of the second conductor 204; and an electrode 205-5 mentioned later.

[0048] The first conductor 203 is arranged along the longitudinal direction of the heater 200. The first conductor 203 is composed of a conductor 203a and a conductor 203b. The conductor 203a is connected to the first heating resistor 202-1a, 202-2a, 202-3a, 202-4a and 202-5a of each heating block. The conductor 203b is connected to the second heating resistor 202-1b, 202-2b, 202-3b, 202-4b and 202-5b of each heating block. In each heating block, the conductor 203a (first conductive portion) electrically connects one end of the substrate in the shorter direction to the electrode 205C1, and the one end is the opposite side of the first heating resistor 202-1a to 202-5a facing the second heating resistor 202-1b to 202-5b. In addition, in each heating block, the conductor 203b (second conductive portion) electrically connects the other end of each substrate of the second heating resistors 202-1b to 202-5b in the shorter direction to the electrode 205C2. The second conductor 204 is divided into 204-1, 204-2, 204-3, 204-4 and 204-5, which are connected to the heating blocks 202-1, 202-2, 202-3, 202-4 and 202-5, respectively. 204-1 to 204-5 electrically connect the other end of the first heating resistors 202-1a to 202-5a in the shorter direction to the electrodes 205-1 to 205-5, and connect one end of the second heating resistors 202-1b to 202-5b in the shorter direction to the electrodes 205-1 to 205-5, whereby 204-1 to 204-5 become the third conductive portion.

[0049] Electrodes 205C1, 205C2, 205-1, 205-2, 205-3, 205-4, and 205-5 are openings of the protective layer 206 to supply power to the first heating resistor 202a and the second heating resistor 202b. Electrode 205C1 (first electrical contact portion) is arranged near one end of the substrate in the longitudinal direction, and electrode 205C2 (second electrical contact portion) is arranged near the other end of the substrate in the longitudinal direction. Electrode 205C1 and electrode 205C2 are common electrodes to supply power to five heating blocks 202-1 to 202-5 via conductor 203a and conductor 203b. On the other hand, electrode 205-1 is an electrode that supplies power to heating block 202-1. Similarly, electrode 205-2 supplies power to heating block 202-2, electrode 205-3 supplies power to heating block 202-3, electrode 205-4 supplies power to heating block 202-4, and electrode 205-5 supplies power to heating block 202-5. Electrodes 205-1 to 205-5 arranged between electrode 205C1 and electrode 205C2 correspond to the third electrical contact portion of each heating block. A contact member (not shown) connected to a power source is brought into contact with each of these electrodes to energize the electrode, thereby supplying power to the first to fifth heating blocks connected to conductors 203a and 203b in parallel with each other.

[0050] By changing the ratio of the power to be supplied to the divided heating blocks 202-1 to 202-5 of the heater 200, it is possible to suppress the temperature rise at the edge of the non-paper passing area where the recording paper does not pass. For example, in the case of fixing the recording paper having a width corresponding to the heating block 202-3, power is supplied only to the heating block 202-3, whereby the temperature rise at the edge of the non-paper passing area can be suppressed by supplying power only to the heating block 202-3.

[0051] Temperature detection structure

[0052] On the sliding surface layer of the heater 200, thermistors Tp1 to Tp5 and Ts1 to Ts5 (temperature detection elements) are arranged in each heating block. Using these thermistors, the temperature of each heating block is detected, and the power to be supplied to the heating block is controlled. In addition, the conductor connected to each thermistor is also arranged on the sliding surface layer of the heater 200. The conductors EG1 and EG2 are respectively connected to one end of the thermistors Tp1 to Tp5 and Ts1 to Ts5, and are connected to the ground potential of the thermistor temperature detection part of the control loop. The conductors ET1 to ET5 are respectively connected to the thermistors Ts1 to Ts5, and are formed in the longitudinal direction until the edge of the heater 200. The conductor EP1 is connected to the edge of the thermistors Tp1 to Tp5 at the side not connected to the conductor EG1. On the sliding surface layer, a protective glass is formed except for the edge of the heater 200 in the longitudinal direction. The portion of each conductor not covered by the protective glass becomes an electrode connected to the flexible sheet 107 as a conductive sheet member. 3E shows a state where the flexible sheet 107 is combined with an electrode on the edge of the heater. On the flexible sheet 107, a conductor pattern similar to the conductors connected to the respective thermistors is formed and welded to a contact located on the edge of the heater so that the flexible sheet 107 overlaps a portion of the heater.

[0053] Contact protection structure

[0054] Figure 4A and 4B A protective structure of a bonding portion between the flexible sheet 107 and the heater 200 is shown. Figure 4A 1 shows a state before the U-shaped housing member 106a is installed in the heater holding member 105, Figure 4B The state after the U-shaped shell member 106a is installed in the heater holding member 105 is shown. The shell member 106a is U-shaped, and if it is assumed that the direction in which the flexible sheet 107 overlaps a part of the heater is the first direction, the shell member 106a includes a pair of contact portions 106a-1 and 106a-2 extending in the second direction (a direction perpendicular to the first direction), and the pair of contact portions are substantially parallel to each other and face each other. In embodiment 1, the shell member 106a is installed together with a part of the heater holding member 105 at the joint portion (connection portion) between the flexible sheet 107 and the heater 200. Then, the contact portion 106a-1 on one side of the pair of contact portions contacts the flexible sheet 107 in one direction of the first direction, and the contact portion 106a-2 on the other side of the pair of contact portions contacts the heater holding member 105 in the opposite direction of the one direction. As a result, the joint portion between the flexible sheet 107 and the heater 200 is held by the pair of contact portions together with the heater holding member 105.

[0055] In other words, the flexible sheet 107 is stacked together with the heater 200 and the heater holding member 105 in the opening portion of the U-shaped shell member 106a at the edge in the longitudinal direction of the heater. By arranging the flexible sheet 107 in this way, the relative movement between the flexible sheet 107 and the heater 200 in the above-mentioned first direction is restricted, but the relative movement between the flexible sheet 107 and the heater 200 in the second direction perpendicular to the first direction is allowed. As a result, the U-shaped shell member 106a receives the force applied to the flexible sheet 107 in the peeling direction, and the force can be prevented from being directly applied to the bonding portion between the flexible sheet 107 and the heater 200 in the peeling direction. Therefore, the occurrence of solder peeling at the bonding portion of the flexible sheet 107 at the edge in the longitudinal direction of the heater 200 and the occurrence of peeling of the electrodes from the heater 200 and the flexible sheet 107 can be suppressed.

[0056] In addition, when the shell member 106a is installed, the electrical connection state between the flexible sheet 107 and the heater 200 is maintained. At the same time, the relative movement between the flexible sheet 107 and the heater 200 in the first direction (the peeling direction of the flexible sheet 107) is limited. In other words, the shell member 106a is used as a limiting member to limit the relative position between the flexible sheet 107 and the heater 200. Movement in the second direction (which is perpendicular to the first direction), that is, in the direction of installing the shell member 106a, is still allowed. Therefore, unlike the case of the prior art using tape or adhesive, the assemblability when installing / removing the shell member 106a can be improved. In addition, in Example 1, the shell member 106a is installed at the joint between the flexible sheet 107 and the heater 200 together with the heater holding member 105, but the present invention is not limited thereto. For example, even if the shell member 106a is directly installed at the joint between the flexible sheet 107 and the heater 200 without the heater holding member 105, a similar effect can be achieved.

[0057] Example 2

[0058] Next, a fixing device according to Embodiment 2 of the present invention will be described. The same constituent elements as those of Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0059] Fig. 6A 1 shows the state before the U-shaped housing member 106b is installed. Figure 6B The state after the U-shaped housing member 106b is installed is shown. Figure 7A diagram showing the heater holding member 105 in a state where the heater 200 is installed, as viewed from the rear surface side of the heater. The housing member 106b includes a pair of contact portions 106b-1 and 106b-2 extending in a second direction perpendicular to the first direction (the first direction is a direction in which the flexible sheet 107 overlaps a portion of the heater 200), and the contact portions 106b-1 and 106b-2 face each other and extend approximately in parallel.

[0060] The pair of contact portions of Embodiment 2 is composed of a contact portion 106b-1 that contacts with a pad member 108 mentioned later in one direction of the first direction, and a contact portion 106b-2 that contacts with the heater holding member 105 in the opposite direction of the one direction. Figure 8 As shown, at least one electric contact member 109 is arranged in the U-shaped housing member 106b. The electric contact member 109 is arranged in the contact portion 106b-2 that contacts the heater holding member 105 along the insertion direction of the housing member 106b. When the U-shaped housing member 106b is installed at the joint portion between the flexible sheet 107 and the heater 200 together with the heater holding member 105, the electric contact member 109 contacts (electrically connects) with the electrode portions 205C1 and 205C2. Electric power is supplied from the power supply via the housing member 106b to the heating resistors 202a and 202b arranged in the heater 200, and the heating resistors 202a and 202b generate heat.

[0061] like Fig. 6A and 6B As shown, the gasket member 108 is arranged between the flexible sheet 107 and the U-shaped shell member 106b overlapping a part of the heater 200. In this way, when the U-shaped shell member 106b is installed at the bonding portion (connecting portion) between the flexible sheet 107 and the heater 200 together with the heater holding member 105, the bonding portion between the flexible sheet 107 and the heater 200 is covered by the gasket member 108. In other words, according to Embodiment 2, the contact portion 106b-1 on one side of the pair of contact portions of the shell member 106b contacts the gasket member 108 instead of the flexible sheet 107, and the contact portion 106b-2 on the other side of the pair of contact portions contacts the heater holding member 105. Thus, the shell member 106b does not directly contact the bonding portion between the flexible sheet 107 and the heater 200, and the possibility of causing damage to the bonding portion between the flexible sheet 107 and the heater 200, which is located at the edge of the heater sliding surface layer in the longitudinal direction, can be reduced.

[0062] The gasket member 108 has a protruding portion that extends in the same direction as the insertion direction of the shell member 106b into the joint portion between the flexible sheet 107 and the heater 200. The protruding portion is configured to engage with a groove portion formed in a contact portion 106b-1 of the contact gasket member 108 in the pair of contact portions of the shell member 106b. By the protruding portion engaging with the groove portion of the shell member 106b, the movement of the protruding portion in a direction perpendicular to the insertion direction of the shell member 106b is restricted. In addition, as described above, the shell member 106b includes a contact portion 106b-1 that contacts the gasket member 108 and a contact portion 106b-2 that contacts the heater holding member 105, and the two contact portions are connected at one end, as shown in FIG. Fig. 6A As shown. Therefore, if the movement of one contact portion 106b-1 of the shell member 106b is restricted, the movement of the other contact portion 106b-2 is also restricted. Since the movement of the shell member 106b as a whole in a direction perpendicular to the insertion direction is restricted, the heater 200 together with the shell member 106b will never shift in a direction perpendicular to the insertion direction of the shell member 106b. As described above, the flexible sheet 107, the heater 200, the heater holding member 105 and the gasket member 108 can be regarded as a component. Then, the groove portion formed in the shell member 106b and the protrusion portion arranged in the gasket member 108 can be regarded as a limiting portion that limits the relative movement of the shell member 106b and the gasket member 108 in a direction perpendicular to the insertion direction of the assembly. By this limiting portion composed of the groove portion and the protrusion portion, the movement of the shell member 106b is restricted, and the movement of the heater 200 relative to the heater holding member 105 in which the shell member 106b is installed in the longitudinal direction of the heater can be prevented.

[0063] When the heater 200 is viewed from the rear surface side, the electrode portions 205C1 and 205C2 of the protective layer and the thermistor electrode portion of the heater sliding surface layer are both located at the edge of the heater in the longitudinal direction. However, in some cases, when viewed from the rear surface side of the heater, the thermistor electrode portion and the electrode portions 205C1 and 205C2 may be arranged at different positions in the longitudinal direction of the heater to ensure an insulation distance between the electrode portions. Fig. 92 is a diagram showing a protective structure of a bonding portion between a flexible sheet 107 and a heater 200 in a case where the electrode portions 205C1 and 205C2 of a protective layer of the heater 200 and the thermistor electrode portion in a sliding surface layer of the heater are arranged at different positions in the longitudinal direction of the heater. In this configuration, a gasket member 108 is arranged to overlap the bonding portion between the flexible sheet 107 and the heater 200 at an edge in the longitudinal direction of the heater 200. In other words, the bonding portion between the flexible sheet 107 and the heater 200 is arranged between the pair of contact portions of the shell member 106b together with a portion of the heater holding member 105, and the gasket member 108 overlaps the bonding portion. By this configuration, relative movement between the flexible sheet 107 and the heater 200 in a direction (first direction) in which the flexible sheet 107 overlaps a portion of the heater 200 is restricted, but relative movement of the shell member 106b in the insertion direction (second direction) is allowed.

[0064] As a result, the U-shaped housing member 106b receives the force applied to the flexible sheet 107 in the stripping direction via the gasket member 108, and this can prevent the force from being directly applied to the bonding portion between the flexible sheet 107 and the heater 200 in the stripping direction. Therefore, the occurrence of solder stripping at the edge in the longitudinal direction of the heater 200 about the bonding portion of the flexible sheet 107, and the occurrence of stripping electrodes from the heater 200 and the flexible sheet 107 can be suppressed. The housing member 106b is also a limiting member when inserted to limit the relative movement between the flexible sheet 107 and the heater in the first direction in which the flexible sheet 107 overlaps a portion of the heater 200 (i.e., in the stripping direction of the flexible sheet 107). However, the movement of the housing member 106b in the second direction perpendicular to the first direction is allowed. Therefore, unlike the case of using a tape or an adhesive, the assemblability when installing / removing the housing member 106b can be improved, just like in Example 1.

[0065] Example 3

[0066] Next, a fixing device according to Embodiment 3 of the present invention will be described. The same constituent elements as those of Embodiment 1 or 2 are denoted by the same reference numerals, and description thereof will be omitted.

[0067] First, refer to Figure 10A to 1 0E describes the features of a heater to which the present invention is applied. Fig. 10A 2 is a cross-sectional view of the heater 200 in the shorter direction (a direction perpendicular to the conveyance direction of the recording material P). Fig. 10B 10C and 10D are plan views of each layer of the heater 200. Fig. 10E shows a state where the flexible sheet 107 is bonded to the electrode on the edge of the heater.

[0068] Conductors LH1 to LH4 are formed on both edges of the sliding surface layer of the heater 200 in the longitudinal direction and on both edges in the shorter direction thereof. On both edges of the heater 200, a flexible sheet 107 composed of a first sheet member connected to one edge of the heater 200 and a second sheet member connected to the other edge of the heater 200 is arranged to overlap with a portion of the heater 200, respectively. On one edge of the flexible sheet 107, conductors LF1 to LF4 similar to the conductors LH1 to LH4 formed on the heater 200 are formed and bonded by solder so that the conductors LH1 to LH4 overlap with the conductors LF1 to LF4. The bonding portion between the conductors LH1 to LH4 and the conductors LF1 to LF4 is a reinforcement area to prevent the flexible sheet 107 from peeling off from the heater 200. Among these reinforcement areas, the conductors LH1 to LH4 formed on the sliding surface layer of the heater 200 correspond to the heater side reinforcement area, and the conductors LF1 to LF4 formed on the flexible sheet 107 correspond to the flexible sheet side reinforcement area. More specifically, LH1 and LH2 in FIG. 10D are first heater side reinforcement areas, and LH3 and LH4 are second heater side reinforcement areas. LF1 to LF2 in FIG. 10E are first flexible sheet side reinforcement areas combined with LH1 and LH2, and LF3 and LF4 are second flexible sheet side reinforcement areas combined with LH3 and LH4. If the combined portion through the reinforcement area is arranged in the paper passing area, the heating resistor 202 on the heater becomes high temperature during printing, and the solder may melt and peel off, so the combined portion is arranged outside the paper passing area, away from the heating resistor 202.

[0069] These reinforcement areas are formed at the edges isolated from the conduction path in the shorter direction of the heater, whereby even if the bonding portion is peeled off, the conduction path from the thermistors Ts and Tp on the heater to the conductors EF1 and EF2 formed on the flexible sheet 107 is not disconnected. In addition, the reinforcement areas are bonded to the inner side of the flexible sheet 107 with respect to the electrode bonding portions EJ1 and EJ2 of the heater 200, which are arranged on one side of the edge of the flexible sheet 107.

[0070] Therefore, when installing Figure 4A , 4B and Fig. 6A , 6BWhen the conductors of the flexible sheet 107 are arranged before the shell member 106a and the gasket member 108 shown, the force in the direction of peeling off the flexible sheet is not directly applied to the bonding parts EJ1 and EJ2, but is applied to the reinforcement area. The bonding of the reinforcement area is performed simultaneously with the bonding of the electrodes at the edge of the heater 200 with the conductors EG1, EG2, EP1 and ET1 to ET5 of the flexible sheet 107. According to Embodiment 3, it is possible to prevent the force in the peeling direction from being applied to the flexible sheet 107 and the bonding part of the electrode from being peeled off after the heater 200 and the flexible sheet 107 are bonded by solder, or to prevent the conductor formed on the flexible sheet from being disconnected due to bending stress that causes conduction failure. As a result, the temperature information about each heating area detected by a plurality of thermistors Tp and Ts arranged on the heater can be stably obtained, and the heating of the heater 200 can be controlled in the absence of temperature dispersion.

[0071] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An image heating device for heating an image formed on a recording material, the image heating device include: a first rotating member; a second rotating member that contacts the first rotating member and forms a nip portion with the first rotating member to nip the recording material between the first rotating member and the second rotating member; a plate-shaped heater disposed in the inner space of the first rotating member, the heater comprising a substrate, a heating resistor formed on the substrate, and an electrode formed on the substrate; a holding member that holds the heater over the entire length of the heater in the longitudinal direction of the heater; a flexible conductive sheet member electrically connected to the electrodes of the heater, the flexible conductive sheet member comprising a conductor pattern bonded to and electrically connected to the electrodes of the heater; and a limiting member that limits a relative position between the flexible conductive sheet member and the heater while maintaining an electrical connection state between the flexible conductive sheet member and the heater, wherein the limiting member is configured to limit relative movement between the flexible conductive sheet member and the heater in a thickness direction of the flexible conductive sheet member, but to allow relative movement in a direction perpendicular to the thickness direction, the thickness direction of the flexible conductive sheet member being a direction in which the flexible conductive sheet member overlaps a portion of the heater, The limiting member includes a first portion facing a surface of the flexible conductive sheet member and a second portion facing a retaining member, the first portion and the second portion extending in a second direction perpendicular to the thickness direction, wherein the first portion contacts the flexible conductive sheet member in one direction of the thickness direction, and the second portion contacts the retaining member in a direction opposite to the one direction, so that a combined portion between the flexible conductive sheet member and the heater is retained together with the retaining member by the first portion and the second portion.

2. The image heating device according to claim 1, in, The image heating device includes a spacer member disposed between the restriction member and the flexible conductive sheet member.

3. The image heating device according to claim 2, in, The spacer member and the restricting member include restricting portions that restrict relative movement to each other in a direction perpendicular to a direction in which an assembly integrating the flexible conductive sheet member, the heater, the holding member, and the spacer member is mounted.

4. The image heating device according to claim 1, in, The heating resistors include: a plurality of heating resistors arranged in a row along the longitudinal direction of the substrate, The heating resistor generates heat by electric power supplied from a power source via a limiting member.

5. An image heating device for heating an image formed on a recording material, the image heating device include: a first rotating member; a second rotating member that contacts the first rotating member and forms a nip portion with the first rotating member to nip the recording material between the first rotating member and the second rotating member; a plate-shaped heater disposed in the inner space of the first rotating member, the heater comprising a substrate, a heating resistor formed on the substrate, and an electrode formed on the substrate; and a flexible conductive sheet member electrically connected to the electrodes of the heater, the flexible conductive sheet member including a conductor pattern bonded to and electrically connected to the electrodes of the heater; wherein the flexible conductive sheet member includes a conductive sheet member side reinforcement area arranged in a bonding portion with respect to the heater, the bonding portion is located on the inner side of an electrical connection portion with respect to the heater, the electrical connection portion is arranged on an edge side of the flexible conductive sheet member, wherein the heater includes a heater-side reinforcement region arranged in the bonding portion at a position facing the conductive sheet member-side reinforcement region, Among them, the conductive sheet member side reinforcement region and the heater side reinforcement region facing each other are bonded.

6. The image heating device according to claim 5, in, The flexible conductive sheet member includes a first flexible conductive sheet member connected to one edge of the heater and a second flexible conductive sheet member connected to another edge of the heater, The heater includes a first heater side reinforcement region combined with a first conductive sheet member side reinforcement region arranged in the first flexible conductive sheet member, and a second heater side reinforcement region combined with a second conductive sheet member side reinforcement region arranged in the second flexible conductive sheet member.

7. The image heating device according to claim 1 or 5, in, The first rotating member is a tubular membrane, and Therein, the heater is arranged on the inner side of the tubular membrane.

8. The image heating device according to claim 7, in, The second rotating member contacts the outer surface of the tubular film and forms a nip in cooperation with the heater via the tubular film.

9. An imaging device, include: an image forming unit that forms an image on a recording material; and a fixing unit that fixes the image formed by the image forming unit on the recording material; Here, the fixing unit is the image heating device according to claim 1 or 5.

Images