JP2023033820A - Fixing device and image forming apparatus - Google Patents

Abstract

To stably and appropriately ground a substrate even if a heater generates heat or stops working, thereby repeating thermal expansion and contraction in a longitudinal direction.SOLUTION: A fixing device (45) comprises: a heater (60) that has a substrate (S) composed of metal material and a resistance heating element (P); a holder (70) that holds the heater (60); and a wire spring (110) that retains the heater (60) on the holder (70). The substrate (S) has a first face (S11), a second face (S12), and side faces (S13), and the wire spring (110) has conductivity and is in contact with the side faces (S13) of the substrate (S) to electrically ground the substrate (S).SELECTED DRAWING: Figure 1

Description

The present disclosure relates to fixing devices and image forming apparatuses.

2. Description of the Related Art Image forming apparatuses such as electrophotographic printers are known to have a fixing device that heats a sheet on which an image is to be formed to fix a developer image. For example, Patent Document 1 discloses a fixing device that includes a heating belt, a resistance heating element that is in sliding contact with the inner surface of the heating belt, and a pressure member that is in pressure contact with the heating belt to form a fixing nip with the heating belt. is disclosed. Further, a second insulating layer is formed on the side opposite to the first insulating layer in the conductive base material formed on the resistance heating element with the first insulating layer interposed therebetween, and at least one opening window is formed in the second insulating layer. is formed, and the conductive substrate exposed in the opening window is grounded through the opening window.

JP 2020-86234 A

In the fixing device disclosed in Japanese Patent Application Laid-Open No. 2002-200310, the manufacturing cost of the fixing device increases because it is necessary to form an opening window in the second insulating layer in order to ground the conductive base material. A heater having a resistance heating element repeats thermal expansion and contraction in the longitudinal direction by generating heat or stopping. Therefore, there is a possibility that the conductive substrate exposed in the opening window and the leaf spring in contact with the conductive substrate are out of relative position, and the conductive substrate cannot be properly grounded by the leaf spring.

An object of the present disclosure is to stably and properly ground a substrate even when thermal expansion and contraction are repeated in the longitudinal direction due to heat generation or stoppage of a heater.

In order to solve the above problems, a fixing device according to a first aspect of the present disclosure includes a heater having a substrate made of a metal material, a resistance heating element arranged on the substrate, and a holder holding the heater. and a fastening member for fastening the heater to the holder so that the heater is held by the holder, the substrate having a first surface on which the resistance heating element is arranged and a side opposite to the first surface. and a side surface that intersects the first surface and connects the first surface and the second surface, wherein the fastening member is conductive, and the side surface of the substrate to electrically ground the substrate.

According to the above configuration, the electrically conductive fastening member abuts against the side surface of the substrate made of a metal material to electrically ground the substrate. , the substrate can be stably and appropriately grounded.

A second aspect of the present disclosure is the fixing device of the first aspect, wherein the fastening member includes a facing portion that faces the first surface of the substrate and supports the first surface, and one end of the facing portion. a first engaging portion that extends from the first engaging portion and engages the holder on one side in the width direction of the heater perpendicular to the longitudinal direction of the heater; and a second engaging portion that engages the holder on the other side, and the first engaging portion and the second engaging portion may abut against the side surface of the substrate. According to the above configuration, since the fastening member abuts the side surface of the substrate on both one side and the other side in the width direction of the heater, the substrate can be more stably grounded.

A third aspect of the present disclosure is the fixing device of the second aspect, wherein the fastening member may be a wire spring. According to the above configuration, by using the wire spring as the fastening member, it is possible to sufficiently reduce the area where the heater and the wire spring overlap. That is, the area required on the heater to hold the heater in the holder can be made sufficiently small. Therefore, the length of the heater and the holder in the longitudinal direction can be shortened to the extent that the required area on the heater can be reduced.

A fourth aspect of the present disclosure is the fixing device according to the second aspect or the third aspect, wherein the holder is formed with insertion holes into which the first engaging portion and the second engaging portion are respectively inserted. may be According to the above configuration, by inserting each of the first engaging portion and the second engaging portion into the insertion hole formed in the holder, the first engaging portion and the second engaging portion are attached to the side surface of the substrate. It can be brought into contact easily.

A fifth aspect of the present disclosure is the fixing device according to any one of the second aspect to the fourth aspect, wherein each of the first engaging portion and the second engaging portion engages with the holder. Grooves may be formed. According to the above configuration, each of the first engaging portion and the second engaging portion engages with the groove formed in the holder, thereby moving the first engaging portion and the second engaging portion to the holder. can be positioned.

A sixth aspect of the present disclosure is the fixing device according to any one of the first to fifth aspects, wherein a connector that supplies power to the heater and sandwiches the heater and the holder; an endless belt in contact with the heater, wherein the shortest distance between the fastening member and the belt may be smaller than the shortest distance between the connector and the belt. According to the above configuration, the shortest distance between the fastening member and the belt is smaller than the shortest distance between the connector and the belt. takes precedence. Therefore, discharge from the belt to the connector can be suppressed.

A seventh aspect of the present disclosure is the fixing device according to the sixth aspect, wherein the fastening member may be arranged between the connector and the belt. According to the above configuration, by arranging the fastening member between the connector and the belt, it is possible to improve the certainty that the fastening member will neutralize the belt when the belt is charged.

An eighth aspect of the present disclosure is the fixing device according to any one of the first aspect to the seventh aspect, wherein the fastening member may be arranged on one end side of the heater in the longitudinal direction. According to the above configuration, the substrate can be grounded on the one end side in the longitudinal direction of the heater.

A ninth aspect of the present disclosure is the fixing device according to any one of the first aspect to the eighth aspect, wherein the fastening member may be arranged on one end side and the other end side in the longitudinal direction of the heater. good. According to the above configuration, the substrate can be grounded on both the one end side and the other end side in the longitudinal direction of the heater.

An image forming apparatus according to a tenth aspect of the present disclosure includes the fixing device according to any one of the first to ninth aspects. According to the above configuration, it is possible to configure an image forming apparatus capable of stably and appropriately grounding the substrate even when thermal expansion and contraction are repeated in the longitudinal direction due to heating or stopping of the heater.

According to one aspect of the present disclosure, the substrate can be stably and appropriately grounded even if thermal expansion and contraction are repeated in the longitudinal direction due to heating or stopping of the heater.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to Embodiment 1 of the present disclosure; FIG. 2 is a cross-sectional view showing a main configuration of a fixing device included in the image forming apparatus shown in FIG. 1; FIG. 3 is a plan view showing a heating unit included in the fixing device shown in FIG. 2; FIG. 4A is an exploded perspective view illustrating a specific configuration of a heater included in the heating unit shown in FIG. 3, and FIG. 4B is a cross-sectional view showing a cross section of the heater shown in FIG. 4 is a diagram illustrating a detailed configuration example of a main part of the fixing device shown in FIG. 3; FIG. 4 is a perspective view showing a specific configuration of a connector included in the heating unit shown in FIG. 3; FIG. 6 is a cross-sectional view showing a configuration example of a main part of the fixing device shown in FIG. 5; FIG. 8 is a perspective view showing a specific configuration of a wire spring included in the fixing device shown in FIG. 7; FIG. FIG. 7 is a plan view showing a heating unit included in a fixing device included in an image forming apparatus according to Embodiment 2 of the present disclosure;

[Embodiment 1]
Embodiment 1 of the present disclosure will be described below with reference to FIGS. 1 to 8. FIG. In this embodiment, as an example of the image forming apparatus 1, a laser printer that forms an image on a sheet S1 using toner will be described.

<Configuration of Image Forming Apparatus 1>
FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus 1 according to Embodiment 1 of the present disclosure. In the following description, the image forming apparatus 1 is exemplified by a monochrome printer that performs image forming processing of a monochrome image, but the present embodiment is not limited to this. It may be a color printer that performs

As shown in FIG. 1, the image forming apparatus 1 includes a housing 2, a paper feeding unit 3, an image forming unit 4, a discharge roller 5, a discharge tray 6, and a main motor M. The housing 2 constitutes an outer container of the image forming apparatus 1 and accommodates the main components of the image forming apparatus 1 .

The sheet feeding unit 3 supplies the sheet S1. The paper feeding unit 3 includes a paper feeding tray 31 , a feeding roller 32 , a pressing plate 33 , a conveying roller 34 and a registration roller 35 . The paper feed tray 31 is a box-shaped member with an open top, and accommodates a predetermined amount of sheets S1. Also, the sheet S1 is a recording medium on which an image forming process is performed, and is made of paper, plastic, or the like.

The feeding roller 32 feeds out the sheet S1 accommodated in the paper feed tray 31 . That is, when the sheet S1 is sent out, the sheet S1 on the sheet feeding tray 31 is pushed toward the feeding roller 32 by the pressing plate 33 and fed to the conveying roller 34 as the feeding roller 32 rotates. The conveying rollers 34 convey the sheet S<b>1 toward the registration rollers 35 . The registration rollers 35 convey the sheet S1 toward the image forming section 4 after aligning the positions of the leading edges of the sheet S1.

The image forming section 4 forms an image by performing an image forming process on the sheet S1 sent out by the paper feeding section 3 . As shown in FIG. 1 , the image forming section 4 includes an exposure device 41 , a transfer device 42 , a charging device 43 , a developing section 44 , a fixing device 45 and a photosensitive drum 46 . The exposure device 41 includes a laser light source (not shown), a polygon mirror 41G, a scanning lens 41L, a polygon motor 41M, and a reflecting mirror 41R.

The polygon mirror 41G is a rotary polygon mirror having six reflecting surfaces on the sides of a regular hexagonal prism. The polygon mirror 41G is for deflecting the light beam L1 emitted by the laser light source in the direction toward the photosensitive drum 46. As shown in FIG. The polygon motor 41M rotates the polygon mirror 41G by being driven by a motor driver (not shown).

The exposure unit 41 deflects the light beam L1 by the polygon mirror 41G, and emits the light beam L1 from the polygon mirror 41G to the surface of the photosensitive drum 46 via the scanning lens 41L and the reflecting mirror 41R. The exposure unit 41 exposes the photosensitive drum 46 by scanning the surface of the photosensitive drum 46 with the light beam L1. As a result, an electrostatic latent image forming a toner image, which will be described later, is formed on the photosensitive drum 46 . Polygon motor 41M is, for example, a brushless DC motor.

The transfer device 42 includes a transfer roller that sandwiches the sheet S1 between itself and a photosensitive drum 46, and transfers the toner image from the photosensitive drum 46 onto the sheet S1. The charger 43 includes, for example, a scorotron-type charger having a charging wire (not shown) and a grid portion. In the charger 43, a high voltage generating circuit (not shown) applies a charging voltage to the charging wire, and a grid voltage is applied to the grid portion, thereby generating corona discharge and uniformizing the surface of the photosensitive drum 46. charged. The developing section 44 includes a developing roller 44R and a toner cartridge 44A containing toner.

In addition to the above description, for example, instead of the transfer roller, the transfer device 42 may include a transfer belt. Further, for example, instead of the scorotron type charger, the charger 43 may include a charging roller.

In the image forming unit 4, after the surface of the photosensitive drum 46 is uniformly charged by the charger 43, the light beam L1 from the exposure unit 41 forms an electrostatic latent image based on the print data from the control unit (not shown). It is formed on the surface of the photosensitive drum 46 . Further, the developing roller 44R supplies toner from inside the toner cartridge 44A to the surface of the photosensitive drum 46 on which the electrostatic latent image is formed.

As a result, the electrostatic latent image is visualized and a toner image is formed on the surface of the photosensitive drum 46 . After that, the sheet S1 fed from the paper feeding unit 3 is conveyed to a transfer position between the photosensitive drum 46 and the transfer device 42, and the toner image formed on the surface of the photosensitive drum 46 is transferred to the sheet S1. transcribed above.

The sheet S<b>1 to which the toner image has been transferred is conveyed to the fixing device 45 by the photosensitive drum 46 and transfer device 42 . The fixing device 45 fixes the toner image formed on the sheet S1. Specifically, the fixing device 45 thermally fixes the toner image on the sheet S1 conveyed from the photosensitive drum 46 and the transfer device 42 using heat generated by the heater 60 described later. The sheet S<b>1 on which the toner image is thermally fixed is discharged onto the discharge tray 6 by the discharge rollers 5 . A specific configuration of the fixing device 45 in this embodiment will be described in detail later.

The main motor M is, for example, a brushless DC motor. The main motor M is connected to a transmission mechanism such as a gear for transmitting its rotational force, and the main motor M functions as a power source for each part housed inside the housing 2 .

<Structure of Fixing Device 45>
2 and 3, the fixing device 45 of this embodiment will be specifically described. FIG. 2 is a cross-sectional view showing the main configuration of the fixing device 45 included in the image forming apparatus 1 shown in FIG. FIG. 3 is a plan view showing the heating unit 51 included in the fixing device 45 shown in FIG.

As shown in FIG. 2, the fixing device 45 includes a heating unit 51 that contacts the sheet S1 on which the toner image is formed and heats the sheet S1, and a pressure roller 52 that presses the sheet S1. One of the heating unit 51 and the pressure roller 52 is pressed toward the other by a pressing portion (not shown). In the fixing device 45, the pressing section is controlled in accordance with instructions from the control section, so that a toner image is formed on the sheet S1 while a predetermined pressure is applied between the heating unit 51 and the pressure roller 52. is performed.

The heating unit 51 includes a heater 60 , a holder 70 , a stay 80 and a belt 90 . The heater 60 is a heating member having a rectangular shape in plan view. The heater 60 has a first surface 60A arranged on the pressure roller 52 side and a second surface 60B facing the first surface 60A. are supported by the holder 70 .

The holder 70 is made of synthetic resin material, for example, and includes a guide surface 70A that guides the belt 90 and a support portion 70B that supports the heater 60 . Guide surface 70A guides belt 90 by contacting inner peripheral surface 90A of belt 90 . The support portion 70B includes a support surface 70B1 that contacts and supports the second surface 60B of the heater 60 . The stay 80 is a reinforcing member that supports the holder 70, and is formed by bending a metal material such as a plate material having greater rigidity than the holder 70, for example, a steel plate, into a substantially U-shaped cross section.

The belt 90 is an endless belt having heat resistance and flexibility. , provided. The belt 90 rotates around the heater 60 , the holder 70 and the stay 80 with the heater 60 , the holder 70 and the stay 80 accommodated therein. Further, the inner peripheral surface 90A of the belt 90 is in contact with the first surface 60A of the heater 60, so that the heat from the heater 60 is transmitted to the sheet S1 via the belt 90. As shown in FIG.

The pressure roller 52 includes a rotary shaft 52A made of a metal material, and an elastic layer 52B made of a synthetic rubber material or the like and covering the surface of the rotary shaft 52A. A nip portion NP for heating and pressing the sheet S1 is formed between the pressure roller 52 and the heater 60 by sandwiching the belt 90 between the pressure roller 52 and the heater 60 .

The pressure roller 52 is driven to rotate in the rotation direction R2 by transmission of the driving force from the main motor M according to the instruction from the control section. That is, the pressure roller 52 and the belt 90 rotate while nipping the sheet S1 conveyed in the conveying direction H, and the belt 90 rotates with the frictional force between the pressure roller 52 and the sheet S1. It is configured to be driven to rotate in the rotation direction R1. As a result, in the fixing device 45, the sheet S1 onto which the toner image has been transferred is conveyed between the heating unit 51 and the pressure roller 52, thereby thermally fixing the toner image onto the sheet S1.

As shown in FIG. 3, the heating unit 51 includes a connector 100 and a wire spring 110, and the connector 100 and the wire spring 110 are provided on one end side of the heater 60 in the longitudinal direction LH. The connector 100 is connected to a power supply (not shown) and supplies power from the power supply to the heater 60 . The connector 100 supplies electric power to the heater 60 while holding the heater 60 and the holder 70 therebetween. The width direction SH of the heater 60 is perpendicular to the longitudinal direction LH of the heater 60 .

The wire spring 110 constitutes a fastening member that fastens the heater 60 to the holder 70 so that the heater 60 is held by the holder 70 . By using the wire spring 110 as the fastening member, the area where the heater 60 and the wire spring 110 overlap can be made sufficiently small. That is, the area required on the heater 60 to hold the heater 60 in the holder 70 can be made sufficiently small. Therefore, the length of the heater 60 and the holder 70 in the longitudinal direction LH can be shortened to the extent that the required area on the heater 60 can be reduced.

<Structure of Heater 60>
Next, the heater 60 will be specifically described with reference to FIG. 4 as well. 4A is an exploded perspective view illustrating a specific configuration of the heater 60 included in the heating unit 51 shown in FIG. 3, and FIG. 4B is an exploded perspective view of the heater 60 shown in FIG. It is sectional drawing which shows a cross section.

As shown in FIGS. 4A and 4B, the heater 60 includes a first insulating layer Z1, a substrate S, a second insulating layer Z2, a resistance heating element P, and a third insulating layer Z3. , provided. The first insulating layer Z1 has a second surface 60B. The substrate S is laminated on the first insulating layer Z1, the second insulating layer Z2 is laminated on the substrate S, the resistive heating element P is arranged on the second insulating layer Z2, and the third insulating layer Z3 is the resistive heating element It is arranged to cover P.

The first insulating layer Z1, the second insulating layer Z2, and the third insulating layer Z3 are made of, for example, an insulator such as a glass material. The third insulating layer Z3 has a first surface 60A, contacts the inner peripheral surface 90A of the belt 90, and serves as a protective layer that protects the resistance heating element P from contact with the inner peripheral surface 90A. Function.

The resistance heating element P includes a power supply terminal T having two terminals T1 and T2, a power supply pattern PE having power supply patterns PE1 and PE2 electrically connected to the terminals T1 and T2, respectively, and a power supply pattern PE electrically connected to the power supply pattern PE. and a connected heating pattern PH. The resistance heating element P is arranged on the substrate S with the second insulating layer Z2 interposed therebetween.

At least the heating pattern PH of the resistance heating element P is made of, for example, a conductive material with excellent heat generation such as nickel-chromium alloy or iron-chromium alloy. heat is generated according to In other words, the current supplied to the heating pattern PH is controlled, and the heat generated by the heating pattern PH is increased or decreased to control the heating of the belt 90 from the heater 60 . The heating unit 51 has a temperature sensor (not shown) for detecting the temperature of the heater 60, and the controller is configured to control the heater 60 using the detection result of the temperature sensor.

The substrate S is made of, for example, a metal material such as stainless steel. The substrate S has a first surface S11, a second surface S12 and a side surface S13. A resistance heating element P is arranged on the first surface S11 via the second insulating layer Z2. The second surface S12 is a surface opposite to the first surface S11 and is covered with the first insulating layer Z1. The side surface S13 intersects the first surface S11 and the second surface S12 and connects the first surface S11 and the second surface S12.

<Main Configuration of Fixing Device 45>
Next, with reference to FIGS. 5 to 8 as well, the main configuration of the fixing device 45 of this embodiment will be specifically described. FIG. 5 is a diagram illustrating a detailed configuration example of the main part of the fixing device 45 shown in FIG. FIG. 6 is a perspective view showing a specific configuration of connector 100 included in heating unit 51 shown in FIG. FIG. 7 is a cross-sectional view showing an example configuration of the main part of the fixing device 45 shown in FIG. FIG. 8 is a perspective view showing a specific configuration of wire spring 110 included in fixing device 45 shown in FIG. 5, illustration of the connector 100 and the third insulating layer Z3 of the heater 60 is omitted.

As shown in FIG. 5, the wire spring 110 electrically grounds the substrate S by contacting the side surface S13 of the substrate S. As shown in FIG. A first engaging portion 112 and a second engaging portion 113, which will be described later, of the wire spring 110 are in contact with the stay 80, and the stay 80 is electrically grounded. Therefore, the wire spring 110 is electrically grounded via the stay 80 .

Alternatively, the first engaging portion 112 and the second engaging portion 113 may be grounded by the stay 80 via a conductive member such as a metal wire without directly contacting the stay 80 . The grounding method of the wire spring 110 described here is an example. As a result, the substrate S can be stably and appropriately grounded even when thermal expansion and contraction are repeated in the longitudinal direction LH due to heat generation or stoppage of the heater 60 .

Since the substrate S is electrically grounded by the wire spring 110, the risk of printing defects on the sheet S1 due to the fixing device 45 can be reduced. Further, the wire spring 110 is arranged on one end side of the heater 60 in the longitudinal direction LH. Thereby, the substrate S can be grounded on the one end side of the heater 60 in the longitudinal direction LH.

The wire spring 110 is installed within an installation area K indicated by a double arrow in FIG. The installation area K is an area between the installation location of the connector 100 electrically connected to the terminals T1 and T2 and the installation location of the belt 90 indicated by the one-dot chain line in FIG. That is, wire spring 110 is arranged between connector 100 and belt 90 . As a result, when the belt 90 is charged due to, for example, contact between the third insulating layer Z3 and the inner peripheral surface 90A of the belt 90, the wire spring 110 can improve the certainty that the belt 90 is discharged. can be done.

Since the wire spring 110 is arranged between the connector 100 and the belt 90, the shortest distance between the wire spring 110 and the belt 90 is configured to be smaller than the shortest distance between the connector 100 and the belt 90. - 特許庁As a result, when the belt 90 is charged, neutralization of the belt 90 by the wire spring 110 is prioritized over discharge from the belt 90 to the connector 100 . Therefore, discharge from the belt 90 to the connector 100 can be suppressed.

Further, an insertion hole 70H is formed on one side of the holder 70 in the width direction SH, and an insertion hole 70J is formed on the other side of the holder 70 in the width direction SH. The first engaging portion 112 of the wire spring 110 is inserted into the insertion hole 70H, and the second engaging portion 113 of the wire spring 110 is inserted into the insertion hole 70J. Thereby, the first engaging portion 112 and the second engaging portion 113 can be brought into contact with the side surface S13 of the substrate S easily.

A groove 70D extending in the width direction SH is formed on one side of the holder 70 in the width direction SH, and a groove 70E extending in the width direction SH is formed on the other side of the holder 70 in the width direction SH. there is The first engaging portion 112 engages with the groove 70D, and the second engaging portion 113 engages with the groove 70E. Thereby, the first engaging portion 112 and the second engaging portion 113 can be positioned with respect to the holder 70 .

The groove 70D is part of the insertion hole 70H, and the groove 70E is part of the insertion hole 70J. As described above, the wire spring 110 is engaged with the holder 70 , so that the wire spring 110 holds the heater 60 in the holder 70 without causing positional deviation between the heater 60 and the holder 70 . Side surfaces S13 of the substrate S are exposed at the ends of the grooves 70D and 70E. By engaging the wire spring 110 with the holder 70, the first engaging portion 112 contacts the side surface S13 of the substrate S within the groove 70D, and the second engaging portion 113 contacts the side surface S13 of the substrate S within the groove 70E. abut.

As a result, it is possible to suppress the occurrence of positional displacement between the heater 60 and the connector 100, thereby preventing electrical damage between the heater 60 and the connector 100 caused by relative positional displacement between the heater 60 and the connector 100. It is possible to suppress the occurrence of poor contact. In addition, it is possible to prevent a shortage of electric power supplied to the heater 60, thereby suppressing a decrease in the heating power of the heater 60 and a decrease in fixing performance. By suppressing the occurrence of misalignment between the heater 60 and the connector 100, the length of the heater 60 and the holder 70 in the longitudinal direction LH can be shortened.

As shown in FIG. 6, the connector 100 includes a connector body 101 and a pair of holding portions 102 and 103. As shown in FIG. A pair of clamping portions 102 and 103 are continuously provided on the connector body 101 and formed to clamp the heater 60 and the holder 70 . The holding portion 102 is electrically connected to a terminal T1 and a terminal T2 of the power supply terminal T of the heater 60 when the connector 100 is attached to the heating unit 51 so as to hold the heater 60 and the holder 70 therebetween. One electrode 104 is provided. The connector 100 can supply power to the heater 60 via the electrodes 104 .

As shown in FIGS. 7 and 8, the wire spring 110 is configured using, for example, a conductive metal wire. The wire spring 110 has a facing portion 111 , a first engaging portion 112 and a second engaging portion 113 . The facing portion 111 faces the first surface S11 of the substrate S and supports the first surface S11. In this case, the facing portion 111 is in contact with the third insulating layer Z3. The first engaging portion 112 extends from one end of the facing portion 111 and engages the holder 70 on one side of the heater 60 in the width direction SH. The second engaging portion 113 extends from the other end of the facing portion 111 and engages the holder 70 on the other side of the heater 60 in the width direction SH.

Specifically, the first engaging portion 112 includes a first extending portion 112A and a first bent portion 112B. The first extending portion 112A continues to one end of the facing portion 111 and extends perpendicularly to the thickness direction of the holder 70 from the one end of the facing portion 111 . The first bent portion 112B continues to the first extended portion 112A and is bent from the first extended portion 112A toward the facing portion 111 side. The first engaging portion 112 is arranged in the insertion hole 70H in an elastically deformed state.

Similarly, the second engaging portion 113 comprises a second extending portion 113A and a second bent portion 113B. The second extending portion 113A continues to the other end of the facing portion 111 and extends perpendicularly to the thickness direction of the holder 70 from the other end of the facing portion 111 . The second bent portion 113B continues to the second extended portion 113A and is bent from the second extended portion 113A toward the facing portion 111 side. The second engaging portion 113 is arranged in the insertion hole 70J in an elastically deformed state.

Since the wire spring 110 has both the function of holding the board S and the function of electrically grounding the board S, the wire spring 110 can be used as a component necessary for holding the board S and electrically grounding the board S. Only the wire spring 110 is sufficient. Therefore, the cost of the parts required for the fixing device 45 can be reduced. Further, along with this, the lengths of the heater 60 and the holder 70 in the longitudinal direction LH can be shortened, and the costs of the fixing device 45 and the image forming apparatus 1 can be easily reduced.

The first extending portion 112A and the second extending portion 113A abut on the side surface S13 of the substrate S. As shown in FIG. As a result, the wire spring 110 contacts the side surface S13 of the substrate S on both one side and the other side of the heater 60 in the width direction SH, so that the substrate S can be more stably grounded.

[Embodiment 2]
Other embodiments of the invention are described below. For convenience of description, members having the same functions as those of the members described in the above embodiments are denoted by the same reference numerals, and description thereof will not be repeated. FIG. 9 is a plan view showing a heating unit 51A included in a fixing device 45A included in an image forming apparatus according to Embodiment 2 of the present disclosure.

As shown in FIG. 9, in the heating unit 51A, the connector 100 and the wire spring 110 are provided not only on one end side of the heater 60 in the longitudinal direction LH, but also on the other end side of the heater 60 in the longitudinal direction LH. That is, the wire springs 110 are arranged on the one end side and the other end side in the longitudinal direction LH of the heater 60 . Thereby, the substrate S can be grounded on both the one end side and the other end side in the longitudinal direction LH of the heater 60 .

In the above-described embodiment, the wire spring 110 is used as a fixing member for fixing the heater 60 to the holder 70 so that the heater 60 is held by the holder 70, but the present invention is not limited to this. For example, the heater 60 may be fastened to the holder 70 using a plate-shaped clip as a fastening member. In this case, the plate-shaped clip may function as an engaging portion that engages the substrate S and the holder 70 and abut on the side surface S13 of the substrate S. As shown in FIG.

The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments is also included in the technical scope of the present disclosure.

1 Image forming apparatus 45, 45A Fixing device 60 Heater 70 Holder 70D, 70E Groove 70H, 70J Insertion hole 90 Belt 90A Inner peripheral surface 100 Connector 110 Wire spring 111 Opposing portion 112 First engaging portion 113 Second engaging portion LH Longitudinal Direction SH Width direction P Resistance heating element S Substrate S11 First surface S12 Second surface S13 Side surface

Claims (10)

a heater having a substrate made of a metal material and a resistance heating element arranged on the substrate;
a holder that holds the heater;
a fastening member that fastens the heater to the holder so that the heater is held by the holder;
The substrate has a first surface on which the resistance heating element is arranged, a second surface opposite to the first surface, and a substrate that intersects the first surface and connects the first surface and the second surface. having an aspect to
The fixing device, wherein the fastening member has conductivity and electrically grounds the substrate by coming into contact with the side surface of the substrate. The fastening member
a facing portion that faces the first surface of the substrate and supports the first surface;
a first engaging portion extending from one end of the facing portion and engaging the holder on one side in the width direction of the heater perpendicular to the longitudinal direction of the heater;
a second engaging portion extending from the other end of the facing portion and engaging with the holder on the other side in the width direction of the heater;
2. The fixing device according to claim 1, wherein said first engaging portion and said second engaging portion are in contact with said side surface of said substrate. The fixing device according to claim 2, wherein the fastening member is a wire spring. 4. The fixing device according to claim 2, wherein said holder is formed with an insertion hole into which each of said first engaging portion and said second engaging portion is inserted. The fixing device according to any one of claims 2 to 4, wherein the holder is formed with grooves with which the first engaging portion and the second engaging portion are engaged. a connector that supplies power to the heater and sandwiches the heater and the holder;
an endless belt whose inner peripheral surface is in contact with the heater,
The fixing device according to any one of claims 1 to 5, wherein the shortest distance between the fastening member and the belt is smaller than the shortest distance between the connector and the belt. The fixing device according to claim 6, wherein the fastening member is arranged between the connector and the belt. The fixing device according to any one of claims 1 to 7, wherein the fastening member is arranged on one end side in the longitudinal direction of the heater. The fixing device according to any one of claims 1 to 8, wherein the fastening member is arranged on one end side and the other end side in the longitudinal direction of the heater. An image forming apparatus comprising the fixing device according to claim 1 .

Images