JP2021012295A - Fixing device - Google Patents

Abstract

To enable increase in the degree of freedom of design in a fixing device equipped with a flat plate-shaped heater.SOLUTION: A fixing device includes: a heater 110; and an endless belt. The heater 110 has a substrate 150 and a heat generating pattern PH formed of a resistance heating element. A belt rotates around the heater. The substrate 150 includes: a body part 151 extending in a longitudinal direction of the substrate; and a bent part 152 extending from an end part of the body part 151 in a direction intersecting with the body part 151. A connector 170 which connects an electric wire 172 for supplying power to the heat generation pattern PH can be fixed to the bent part 152.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fixing device provided with a flat plate heater.

Conventionally, a fixing device provided with a flat plate-shaped heater is known (see Patent Document 1). The heater is provided with terminals at the ends in the longitudinal direction, and a connector for supplying power to the terminals is connected.

JP 2015-191734

By the way, since the connector is fixed to the end portion in the longitudinal direction of the heater, it is necessary to avoid interference with other parts such as gears.

Therefore, an object of the present invention is to increase the degree of freedom in designing a fixing device provided with a flat plate-shaped heater.

In order to solve the above problems, the fixing device according to the present invention includes a heater and an endless belt. The heater has a substrate and a heating pattern composed of a resistance heating element. The belt rotates around the heater. The substrate has a main body portion provided with a heat generating pattern and extending in the longitudinal direction of the substrate, and a bent portion extending in a direction intersecting the main body portion from an end portion in the longitudinal direction of the main body portion. A connector for connecting an electric wire for supplying power to the heat generation pattern can be fixed to the bent portion.

According to this configuration, since the connector is fixed to the bent portion, the degree of freedom in design of the fixing device including the flat plate-shaped heater can be increased.

Further, the connector may be configured so that it can be inserted into the bent portion from the end face direction of the bent portion.

Further, the connector may be configured so that it can be inserted from the first end surface side of the end surface of the bent portion, which is separated from the main body portion in the extending direction of the bent portion.

Further, the connector may be configured so that it can be inserted from the second end surface side of the end surface of the bent portion facing the lateral side of the substrate.

Further, the bent portion may be configured to have a hole, a notch, or a protrusion to prevent the connector from coming off.

According to this, the connector is stably held in the bent portion.

Further, the heater may further have a power supply terminal for conducting power with the heat generation pattern to supply power to the heat generation pattern, and the power supply terminal may be configured to be located in the main body.

According to this, the heater can be easily manufactured.

Further, the substrate may be made of metal.

According to this, the main body portion and the bent portion of the substrate can be easily formed.

According to the present invention, it is possible to increase the degree of freedom in designing a fixing device including a flat plate heater.

It is sectional drawing which shows the laser printer which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the fixing device. It is a perspective view which shows the heater and a connector partially disassembled. FIG. 3 is a cross-sectional view taken along the line II in FIG. 3 in a state where a connector is connected to the heater. It is a perspective view which shows the heater and the connector in 2nd Embodiment partially disassembled. It is a perspective view which shows the heater and the connector in 3rd Embodiment partially disassembled. It is a figure (a), (b) which shows another form of a substrate.

Next, the first embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the laser printer 1 mainly includes a supply unit 3, an exposure device 4, a process cartridge 5, and a fixing device 8 in a housing 2.

The supply unit 3 is provided in the lower part of the housing 2, and mainly includes a supply tray 31 for accommodating the sheet S, a pressing plate 32, and a supply mechanism 33. The sheet S housed in the supply tray 31 is moved upward by the pressing plate 32 and supplied to the process cartridge 5 by the supply mechanism 33.

The exposure device 4 is arranged in the upper part of the housing 2 and includes a light source device (not shown), a polygon mirror, a lens, a reflector, and the like, which are indicated by omitting reference numerals. In the exposure apparatus 4, the light beam based on the image data emitted from the light source apparatus is scanned at high speed on the surface of the photoconductor drum 61 to expose the surface of the photoconductor drum 61.

The process cartridge 5 is arranged below the exposure device 4, and is removable from the housing 2 through an opening formed when the front cover 21 provided in the housing 2 is opened. The process cartridge 5 includes a drum unit 6 and a developing unit 7. The drum unit 6 mainly includes a photoconductor drum 61, a charger 62, and a transfer roller 63. Further, the developing unit 7 is detachable from the drum unit 6, and mainly includes a developing roller 71, a supply roller 72, a layer thickness regulating blade 73, and an accommodating portion 74 for accommodating toner. ..

In the process cartridge 5, the surface of the photoconductor drum 61 is uniformly charged by the charger 62 and then exposed by the light beam from the exposure device 4, so that the photoconductor drum 61 is statically charged based on the image data. An electro-latent image is formed. Further, the toner in the accommodating portion 74 is supplied to the developing roller 71 via the supply roller 72, enters between the developing roller 71 and the layer thickness regulating blade 73, and forms a thin layer having a constant thickness on the developing roller 71. Be carried. The toner supported on the developing roller 71 is supplied from the developing roller 71 to the electrostatic latent image formed on the photoconductor drum 61. As a result, the electrostatic latent image is visualized and a toner image is formed on the photoconductor drum 61. After that, the sheet S is conveyed between the photoconductor drum 61 and the transfer roller 63, so that the toner image on the photoconductor drum 61 is transferred onto the sheet S.

The fixing device 8 is arranged on the downstream side of the process cartridge 5 in the transport direction of the sheet S. The sheet S on which the toner image is transferred passes through the fixing device 8 to fix the toner image. The sheet S on which the toner image is fixed is discharged onto the discharge tray 22 by the transfer rollers 23 and 24.

As shown in FIG. 2, the fixing device 8 includes a heating unit 81 and a pressure roller 82. One of the heating unit 81 and the pressure roller 82 is urged against the other by an urging mechanism (not shown).

The heating unit 81 includes a heater 110, a holder 120, a stay 130, and a belt 140. The heater 110 is a flat plate-shaped heater and is supported by the holder 120. The structure of the heater 110 will be described in detail later.

The holder 120 is made of resin or the like, and has a guide surface 121 that contacts and guides the inner peripheral surface of the belt 140. The holder 120 has heater support surfaces 122 and 123 that support the heater 110. The heater support surface 122 comes into contact with the surface of the heater 110 on the side far from the pressurizing roller 82 to support the heater 110. The heater support surface 123 contacts the heater 110 in the transport direction of the sheet S to support the heater 110.

The stay 130 is a member that supports the holder 120, and is formed by bending a plate material having a higher rigidity than the holder 120, for example, a steel plate, in a substantially U-shape in cross section.

The belt 140 is an endless belt having heat resistance and flexibility, and has a base material and a fluororesin layer covering the base material. As the base material, a heat-resistant resin such as polyimide or a metal such as stainless steel can be used. The heater 110, the holder 120 and the stay 130 are arranged inside the belt 140. The inner peripheral surface of the belt 140 comes into contact with the heater 110 and rotates around the heater 110.

The pressure roller 82 has a metal shaft 82A and an elastic layer 82B that covers the shaft 82A. The pressure roller 82 sandwiches the belt 140 with the heater 110 to form a nip portion NP for heating and pressurizing the sheet S.

The pressurizing roller 82 is configured so that a driving force is transmitted from a motor (not shown) provided in the housing 2 to drive the pressurizing roller 82 rotationally, and the frictional force with the belt 140 (or the seat S) is driven by the rotational driving. The belt 140 is driven to rotate. As a result, the sheet S on which the toner image is transferred is conveyed between the pressure roller 82 and the heated belt 140 so that the toner image is thermally fixed.

As shown in FIGS. 3 and 4, the heater 110 includes the substrate 150, the first insulating layer G1, the second insulating layer G2, the heat generating pattern PH, the feeding pattern PE, the feeding terminal T, and the protective layer C. And have. The heater 110 is supplied with power by connecting the connector 170.

The substrate 150 has a main body portion 151 and a bent portion 152. The substrate 150 is made of metal. In this embodiment, the substrate 150 is made of stainless steel. As an example, the substrate 150 is made by bending a rectangular flat plate.

The main body portion 151 is a portion extending in the longitudinal direction of the substrate 150. The main body 151 has a rectangular shape elongated in the longitudinal direction of the substrate 150. The main body 151 has a first surface 151A and a second surface 151B. The first surface 151A and the second surface 151B are surfaces orthogonal to the direction in which the heating unit 81 and the pressure roller 82 are arranged. A heat generation pattern PH is provided on the first surface 151A of the main body 151. In the present embodiment, the heater 110 is arranged so that the second surface 151B of the main body 151 faces the pressurizing roller 82.
In the following description, the longitudinal direction of the substrate 150 is also simply referred to as the "longitudinal direction", and the lateral direction of the substrate 150 is also referred to as the "minor direction". Here, in the present embodiment, the lateral direction is the same as the moving direction of the belt 140 in the nip portion NP.

The connector 170 can be fixed to the bent portion 152. The bent portion 152 extends from an end portion in the longitudinal direction of the main body portion 151 in a direction intersecting the main body portion 151. In the present embodiment, the bent portion 152 extends from the longitudinal end portion of the main body portion 151 in the direction orthogonal to the main body portion 151. The bent portion 152 has a hole 152H that prevents the connector 170 from coming off.

The bent portion 152 has three end faces. Specifically, the bent portion 152 has a first end surface 152A, a second end surface 152B, and a third end surface 152C. The first end surface 152A is a surface separated from the main body 151A in the extending direction of the bent portion 152, and has the same direction as the first surface 151A of the main body 151. The second end surface 152B and the third end surface 152C are surfaces orthogonal to the first end surface 152A, and are surfaces facing in the lateral direction.

The first insulating layer G1 is made of an insulator such as a glass material. The first insulating layer G1 is provided on the first surface 151A of the main body 151.

The second insulating layer G2 is made of an insulator such as a glass material. The second insulating layer G2 is provided on the second surface 151B of the main body 151. The second surface 151B is a surface opposite to the first surface 151A.

The heat generation pattern PH, the power supply pattern PE, and the power supply terminal T are provided on the opposite sides of the main body portion 151 with the first insulating layer G1 interposed therebetween. The heat generation pattern PH is composed of a resistance heating element that generates heat when energized. In the present embodiment, the heat generation pattern PH has a U-shape formed along both ends in the lateral direction of the main body portion 151 and one end in the longitudinal direction and folded back at one end in the longitudinal direction of the main body portion 151.

The power supply pattern PE is a pattern for electrically connecting the power supply terminal T and the heat generation pattern PH. The power supply pattern PE and the power supply terminal T are made of a conductive material having a resistance value smaller than that of the heat generation pattern PH.

The power supply terminal T is a terminal for supplying electricity to the heat generation pattern PH. The power supply terminal T is located at the main body portion 151. In this embodiment, two power feeding terminals T are provided at the other end of the substrate 150 in the longitudinal direction. The power supply terminal T conducts with the heat generation pattern PH and the power supply pattern PE. In the present embodiment, the power feeding terminal T is formed by plating the first insulating layer G1 with a metal such as copper. As shown in FIG. 4, each power supply terminal T can be connected to the connector 170, and is connected to the power supply in the housing 2 via the electric wire 172 of the connector 170.

The protective layer C is made of an insulator such as a glass material, and covers a part of the power supply pattern PE and the heat generation pattern PH.

The connector 170 is a member for connecting the electric wire 172 for supplying power to the heat generation pattern PH to the heater 110. The connector 170 has two feeding electrodes 171 and two electric wires 172 and a housing 173.

The feeding electrode 171 is an electrode that comes into contact with the feeding terminal T. The electric wire 172 is a wiring for connecting the power supply in the housing 2 and the power feeding electrode 171.

The housing 173 is a member that holds the feeding electrode 171 and fixes the connector 170 to the heater 110. The housing 173 has a groove 173A, a hook 173B, an electrode holding portion 173C, and a partition wall 173D. The housing 173 is made of an insulating material such as a heat resistant resin.

The groove 173A extends in the lateral direction of the substrate 150 and opens on both sides in the lateral direction and toward the substrate 150 side. The groove 173A positions the connector 170 by inserting the bent portion 152.

The hook 173B is a member that enters the hole 152H of the bent portion 152 and prevents the connector 170 from coming off. The hook 173B is adapted to bend outward in the longitudinal direction when the connector 170 is inserted into the bent portion 152.

The electrode holding portion 173C is provided inside the housing 173. The electrode holding portion 173C holds the feeding electrode 171. The partition wall 173D is a wall provided inside the housing 173 and partitioning the two feeding electrodes 171 so as not to come into contact with each other.

The connector 170 can be inserted into the bent portion 152 from the end face direction of the bent portion 152. In the present embodiment, as shown by the arrow in FIG. 3, the connector 170 is inserted from the first end surface 152A side of the end surface of the bent portion 152, which is separated from the main body portion 151 in the extending direction of the bent portion 152. It is possible.

Next, the operation and effect of the fixing device 8 according to the present embodiment will be described.
The substrate 150 of the heater 110 has a main body portion 151 extending in the longitudinal direction and a bent portion 152 extending in a direction orthogonal to the main body portion 151, and the connector 170 is fixed by the bent portion 152. Therefore, it is possible to prevent the connector 170 from interfering with other parts such as the gear of the pressure roller 82. As a result, the degree of freedom in designing the fixing device provided with the flat plate-shaped heater can be increased.

Further, since the bent portion 152 has a hole 152H that prevents the connector 170 from coming off, the connector 170 is stably held by the bent portion 152.

Further, since the power supply terminal T is located at the main body portion 151, the heater 110 can be easily manufactured even when the power supply terminal T is located at the bent portion 152.

The substrate 150 is made of metal. Therefore, for example, by bending and processing a metal plate, the main body portion 151 and the bent portion 152 can be easily produced as compared with the case where other members are processed.

Next, the second embodiment will be described. In the following description, members having substantially the same structure as that of the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the first embodiment, the connector 170 can be inserted from the first end face side 152A of the end faces of the bent portion 152 (see FIG. 3), but as shown by an arrow in FIG. 5, the connector 170 May be configured so that it can be inserted from the second end face side 152B of the bent portion 152 facing the lateral direction of the substrate 150. Although not shown, the direction in which the connector 170 is inserted may be the direction of the third end surface 152C. Even in such a case, since the connector 170 is fixed by the bent portion 152, it is possible to prevent the connector 170 from interfering with other parts.

Next, the third embodiment will be described. In the following description, members having substantially the same structure as that of the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.
In the first embodiment, the power supply terminal T is located at the main body portion 151, but as shown in FIG. 6, the power supply terminal T may be located at the bent portion 252.

Specifically, the substrate 250 of the heater 210 according to the third embodiment has a main body portion 251 and a bent portion 252. The bent portion 252 extends from the longitudinal end of the main body portion 251 in a direction intersecting the main body portion 151. The bent portion 252 is provided with a first insulating layer G1. The power supply terminal T is located on the bent portion 252 via the first insulating layer G1. The power supply pattern PE connecting the heat generation pattern PH and the power supply terminal T is provided across both the main body portion 251 and the bent portion 252. When the connector 270 is fixed to the bent portion 252, the power supply terminal T is connected to the power supply electrode 217 of the connector 170.
Even in such a third embodiment, since the connector 270 is fixed by the bent portion 252, it is possible to prevent the connector 170 from interfering with other parts.

In the case of manufacturing the heater 210, the first insulating layer G1 and the feeding pattern PE may be provided after the bent portion 252 is formed by bending, or the first insulating layer G1 and the feeding pattern PE may be provided. The bending process may be performed after providing the above.

The present invention is not limited to the above embodiment, and can be used in various forms as illustrated below.

In the above embodiment, the bent portion of the substrate has a hole 152H for preventing the connector from coming off, but as shown in FIG. 7A, the bent portion 352 prevents the connector from coming off. It may have a notch of 352K. Further, as in the substrate 450 shown in FIG. 7B, the bent portion 452 may have a protrusion 452T that prevents the connector from coming off.

In the above embodiment, the bent portion 152 extends in a direction orthogonal to the main body portion 151, but the bent portion is not limited to the direction orthogonal to the main body portion 151 and may extend in a direction intersecting the main body portion 151.

In the above embodiment, the heat generation pattern PH has a U-shape that is folded back at one end in the longitudinal direction, but the shape of the heat generation pattern PH is not particularly limited and may be a bellows shape or a linear shape.

In the above embodiment, the protective layer C is provided, but the present invention is not limited to this, and the protective layer C may not be provided.

In the above embodiment, the surface of the second insulating layer G2 on the side of the heater 110 on which the heat generation pattern PH is not formed is brought into contact with the belt 140, but the present invention is not limited to this, and the heat generation pattern PH of the heater 110 is The surface on the side to be formed may be brought into contact with the belt 140.

In the above embodiment, the substrate is stainless steel, but the substrate may be a metal or alloy other than stainless steel, or may be a material other than metal.

In the above embodiment, the present invention is applied to the laser printer 1, but the present invention is not limited to this, and the present invention may be applied to other image forming devices such as a copier and a multifunction device.

In addition, each element described in the above-described embodiment and modification may be arbitrarily combined and implemented.

8 Fixing device 110 Heater 140 Belt 150 Board 151 Main body 152 Folded part 152H Hole 170 Connector C Protective layer G1 First insulating layer G2 Second insulating layer PE Power supply pattern PH Heat generation pattern S sheet T Power supply terminal

Claims (7)

A heater having a substrate and a heating pattern composed of a resistance heating element,
An endless belt that rotates around the heater,
With
The substrate has a main body portion provided with the heat generation pattern and extending in the longitudinal direction of the substrate, and a bent portion extending in a direction intersecting the main body portion from the longitudinal end portion of the main body portion.
The bent portion is a fixing device characterized in that a connector for connecting an electric wire for supplying power to the heat generation pattern can be fixed. The fixing device according to claim 1, wherein the connector can be inserted into the bent portion from the end surface direction of the bent portion. The fixing according to claim 2, wherein the connector can be inserted from the first end surface side of the bent portion, which is separated from the main body portion in the extending direction of the bent portion. apparatus. The fixing device according to claim 2, wherein the connector can be inserted from the second end surface side of the bent portion facing the lateral direction of the substrate. The fixing device according to any one of claims 1 to 4, wherein the bent portion has a hole, a notch, or a protrusion that prevents the connector from coming off. The heater further has a power supply terminal for conducting power to the heat generation pattern and feeding the heat generation pattern.
The fixing device according to any one of claims 1 to 5, wherein the power feeding terminal is located in the main body portion. The fixing device according to any one of claims 1 to 6, wherein the substrate is a metal.

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