JP2001282025A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device whose rising time is shortened even in the case of a fixing device having a heating roller constituted so that a cylindrical heating layer body may be brought into press-contact with the inner peripheral surface of a cylindrical metallic base substance by a cylindrical spring body. SOLUTION: This fixing device is provided with the heating roller 10 fixing an unfixed toner image on recording paper in cooperation with the pressure roller, and the roller 10 is constituted of the cylindrical metallic base substance 11. Then, the cylindrical heating layer body 14 is provided on the inner peripheral surface of the substance 11 through a cylindrical insulating layer body 13, and the cylindrical spring body 17 is provided on the inner peripheral surface of the layer body 14 through a cylindrical insulating layer body 15, then a heat insulating layer body 16 is provided between the layer body 14 and the spring body 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cylindrical heat generating layer provided on the inner peripheral surface of a cylindrical metal substrate (cylindrical core) via a cylindrical insulating layer. The present invention relates to a fixing device having a heating roller provided on an inner peripheral surface thereof with a cylindrical spring body that presses a cylindrical heat generating layer together with a cylindrical metal base with a cylindrical insulating layer through a cylindrical insulating layer. .

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, a heating roller 1 for fixing an unfixed toner image on recording paper in cooperation with a pressure roller (not shown) has been used in a fixing device. A cylindrical heat generating layer 4 is provided on the inner peripheral surface of the cylindrical metal base 2 with a cylindrical insulating layer 3 interposed therebetween.
A cylindrical spring body 6 was provided on the inner peripheral surface of the cylindrical heat generating layer 4 via a cylindrical insulating layer 5, and a release layer 7 was provided on the outer peripheral surface of the cylindrical metal base 2. Things are known.

[0003] The cylindrical heating layer 4 is formed of, for example, a heating resistor pattern. The structure for energizing the cylindrical heating layer 4 is, for example, as follows.

That is, the fixing device is provided with a non-conductive hollow resin brush holder. The cylindrical metal substrate 2 is provided with a power supply cap member at the side end opening. A slidable power supply brush is provided in the hollow resin brush holder. The power supply brush is pressed against the power supply cap member by a spring member, and is connected to the power supply brush via a conductive wire disposed in the hollow resin brush holder. The power is supplied to the power supply cap member.

[0005]

However, in this conventional heating roller 1, the cylindrical spring body 6 is in contact with the inner peripheral surface of the cylindrical heating layer body 4 via the insulating layer body 5. In addition, the heat of the cylindrical heat generating layer body 4 escapes toward the cylindrical spring body 6 via the insulating layer body 5, and as a result, there is a problem that the rise time of the fixing device is slow.

FIG. 2 shows the rise time of the heating roller having a configuration in which the cylindrical heating layer 4 is fixed to the inner peripheral surface of the cylindrical metal base 2 with an adhesive, and the cylindrical heating layer 4 is attached to the cylindrical spring 6.
FIG. 4 is a graph comparing the rise time of a pressure roller 1 having a configuration in which the pressure roller 1 is pressed against the inner peripheral surface of a cylindrical metal substrate 2. As shown in FIG. 6, the rise time T1 until the outer peripheral surface of the pressure roller 1 is pressed against the inner peripheral surface of the cylindrical metal substrate 2 to reach 180 ° C. Pressurization in a configuration in which the conventional cylindrical heat generating layer body 4 is pressed against the inner peripheral surface of the cylindrical metal base body 2 by the cylindrical spring body 6 later than the rising time T2 of the heating roller configured to be fixed to the inner peripheral surface of the metal roller 2 The roller 1 has a problem that it takes too much time to start up and also takes too much power.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heating roller having a configuration in which a cylindrical heating layer is pressed against the inner peripheral surface of a cylindrical metal base by a cylindrical spring. An object of the present invention is to provide a fixing device that can reduce the rise time even if the fixing device has the fixing device.

[0008]

According to a first aspect of the present invention, there is provided a fixing device having a heating roller for fixing an unfixed toner image on recording paper in cooperation with a pressure roller, wherein the heating roller is a cylindrical metal. A cylindrical heat generating layer is provided on the inner peripheral surface of the cylindrical metal substrate via a cylindrical insulating layer, and a cylindrical insulating layer is disposed on the inner peripheral surface of the cylindrical heat generating layer. Wherein a cylindrical heat insulating layer is provided between the cylindrical heat generating layer and the cylindrical spring.

According to the first aspect of the present invention, since the cylindrical heat insulating layer is provided between the cylindrical heat generating layer and the cylindrical spring body, the heat of the cylindrical heat generating layer is cylindrical. It becomes difficult to be transmitted to the spring body, and the heat of the cylindrical heat generating layer is exclusively guided to the outer peripheral surface of the cylindrical metal base, so that the cylindrical heat generating layer is pressed against the inner peripheral surface of the cylindrical metal base by the cylindrical spring. Even with a fixing device having a heating roller configured as described above, the rise time of the fixing device can be reduced.

The fixing device according to the present invention is characterized in that the thickness of the cylindrical heat insulating layer is 2 mm or less.

According to the second aspect of the present invention, the rise time of the fixing device can be efficiently shortened without increasing the material cost required for the cylindrical heat insulating layer more than necessary.

According to a third aspect of the present invention, in the fixing device, the cylindrical spring body is restrained from moving in the thrust direction of the cylindrical metal base.

According to the third aspect of the present invention, the cylindrical spring body moves in the thrust direction of the cylindrical metal base during rotation of the heating roller, and comes into contact with the cylindrical heat generating layer body or the power supply cap member to be short-circuited. Can be prevented.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 3, reference numeral 10 denotes a heating roller. The heating roller 10 includes a cylindrical metal base 11. The cylindrical metal substrate 11 is formed using a metal material such as iron, aluminum, copper, and stainless steel.

A release layer 12 is provided on the outer peripheral surface of the cylindrical metal base 11. The release layer 12 has a thickness of, for example, 10 μm to 30 μm, and is formed by coating the outer peripheral surface of the cylindrical metal substrate 11 with a PFA or PTFE material.

A cylindrical heat generating layer 14 is provided on the inner peripheral surface of the cylindrical metal base 11 with a cylindrical heat-resistant insulating layer 13 interposed therebetween. The cylindrical heat-resistant insulating layer 13 is made of a resin material such as polyimide. A cylindrical heat-resistant insulating layer 15 is provided on the inner peripheral surface of the cylindrical heating layer 14. The cylindrical heating layer body 14 is made of, for example, a metal foil (heating resistance pattern) such as stainless steel, and has a layer thickness of, for example, 25 μm to 100 μm.

The same material as that of the cylindrical heat-resistant insulating layer 13 is used for the material of the cylindrical heat-resistant insulating layer 15, and the thickness of the cylindrical heat-resistant insulating layer 13 is, for example, 25 μm.
To 100 μm. These cylindrical heat-resistant insulating layers 1
3 is formed by applying a sheet or a coating to both surfaces of the cylindrical heating layer body 14.

A cylindrical heat-resistant heat-insulating layer 16 is provided on the inner peripheral surface of the cylindrical heat-generating layer 14 with a cylindrical heat-resistant insulating layer 15 interposed therebetween. This cylindrical heat-insulating layer 16 has a temperature of 500 ° C.
Felt member made of material that does not ignite even at high temperatures,
For example, it is formed using a material such as Nomex or SC paper. It is desirable that the layer thickness of the cylindrical heat-resistant and heat-insulating layer body 16 be 2 mm or less. The reason will be described later.

A cylindrical spring body 17 is provided on the inner peripheral surface of the cylindrical heat-resistant and heat-insulating layer body 16. Cylindrical heat-resistant insulating layer 13, cylindrical heating layer 14, and cylindrical heat-resistant insulating layer 15
The cylindrical heat-resistant and heat-insulating layer body 16 is pressed against the inner peripheral surface of the cylindrical metal base 11 by the cylindrical spring body 17. The cylindrical spring body 17 is formed by rolling a rectangular SUS plate. The layer thickness of the cylindrical spring body 17 is, for example, 50
μm to 200 μm.

As shown in FIG. 4, a cylindrical heat-resistant insulating layer 1
3 is longer than the entire length of the cylindrical heat generating layer 14 in the axial direction, and protrudes at least 2.5 mm from the end face of the cylindrical heat generating layer 14. Cylindrical heat-insulating layer 1
6 is substantially the same as the overall length in the axial direction of the cylindrical heat-resistant insulating layer body 15 and shorter than the entire axial length of the cylindrical heating layer body 14. 14
a and 14a are provided. A power supply cap member (not shown) is fitted into both ends of the cylindrical metal base 11, and the power supply cap member is brought into contact with the power supply contact portions 14a, 14a. The axial width of the power supply contact portions 14a, 14a is, for example, 2 mm or more. The overall axial length of the cylindrical spring body 17 is shorter than the overall axial length of the cylindrical heat-resistant insulating layer body 15,
From the end face of the cylindrical spring body 17, the cylindrical heat-resistant insulating layer 1
It is desirable that the length up to the end face of No. 5 be 2.5 mm or more in order to achieve insulation.

As shown in FIG. 5, the heating roller 10 has a cylindrical heat resistant insulating layer 13, a cylindrical heat generating layer 14, a cylindrical heat resistant insulating layer 15,
After disposing the cylindrical heat-resistant and heat-insulating layer 16, a cylindrical spring 17 having a diameter smaller than the inner diameter of the cylindrical heat-resistant and heat-insulating layer 16 is inserted into the cylindrical base 11 from the end face opening thereof, and the cylindrical spring 17 is inserted. Formed by releasing the force being applied to the The cylindrical spring body 17 swells outward due to its resilience due to the release of the force, whereby the cylindrical heat-resistant insulating layer 13, the cylindrical heat-generating layer 14, the cylindrical heat-resistant insulating layer 15, the cylindrical heat-resistant insulating layer 15, The heat insulating layer 16 is pressed against the inner peripheral surface of the cylindrical metal base 11.

According to the heating roller 10, the heat of the cylindrical heat generating layer 14 is less likely to be transmitted to the cylindrical spring 17, so that the rise time can be shortened.

However, when the cylindrical heat-resistant and heat-insulating layer 16 itself has a heat capacity, and as shown in FIG.
The rise time T3 becomes slow, and the layer thickness becomes 3 mm, for example.
Then, the rising time T4 is further delayed.
On the other hand, when the thickness of the cylindrical heat-resistant and heat-insulating layer 16 is, for example, 2 mm and 1 mm, the rise time T
5, T6 is almost the same, the rise time of the heating roller having a configuration in which the cylindrical heating layer is fixed to the inner peripheral surface of the cylindrical metal base with an adhesive earlier than the rise time T3 when the layer thickness is 2.5 mm. Therefore, the thickness of the cylindrical heat-resistant and heat-insulating layer 16 is desirably set to 1 mm to 2 mm.

The cylindrical spring body 17 may be displaced in the axial direction (thrust direction) as the heating roller 10 rotates, whereby the cylindrical spring body 17
Contacting a may cause a short circuit in the electrical circuit. In order to prevent this, as shown in FIG. 7, as shown in FIG. 7, cut-off portions 17 a are provided at both ends of the cylindrical spring body 17, and the cylindrical heat-resistant insulating layer 15 and the cylindrical heat-resistant insulating layer 16 are formed. Sections 15a and 16a are provided at both ends. The section 17a is extended to the inner peripheral end face of the cylindrical metal base 11, and the section 17a is fixed to the inner peripheral end face of the cylindrical metal base 11 by fixing means such as spot welding, eyelets, and rivet fastening. . The sections 15a and 16a serve to prevent the section 17a from contacting the power supply contact section 14a of the cylindrical heat generating layer 14.

Thus, the movement of the cylindrical spring body 17 in the thrust direction is restricted, and the cylindrical spring body 17 moves in the thrust direction of the cylindrical metal base 11 while the heating roller 10 is rotating, so that the heating layer body or the power supply is provided. It is possible to prevent the phenomenon of short-circuit due to contact with the cap member.

In the embodiment of the present invention, the cylindrical spring body 17 is formed by rolling a rectangular SUS plate, but a coil spring may be used as the cylindrical spring body 17. This coil spring has a cylindrical metal base 1
When the coil spring is inserted into the cylindrical metal base 11, the coil spring is contracted by pulling both ends in the direction in which the coil spring extends in order to insert the coil spring into the cylindrical metal base 11. In this state, the coil spring is inserted into the cylindrical metal base 11 to stop the tension and release the force applied to the coil spring. by this,
The coil spring is restored to its original state, and the cylindrical heat-resistant insulating layer 1
3. The cylindrical heat-generating layer 14, the cylindrical heat-resistant insulating layer 15, and the cylindrical heat-resistant insulating layer 16 are pressed against the inner peripheral surface of the cylindrical metal base 11.

[0027]

According to the present invention, since the heat insulating layer is provided between the heat generating layer and the cylindrical spring, the heat of the heat generating layer is less likely to be transmitted to the cylindrical spring, and the heat is generated exclusively. A fixing device having a heating roller configured to press the cylindrical heating layer body against the inner peripheral surface of the cylindrical metal substrate by a cylindrical spring body because heat of the layer body is guided to the outer peripheral surface of the cylindrical metal substrate. However, the rise time can be shortened.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a conventional heating roller.

FIG. 2 is a graph used to explain the rise time of a conventional heating roller.

FIG. 3 is a vertical sectional view of a heating roller according to the present invention.

FIG. 4 is a horizontal sectional view of the heating roller shown in FIG.

FIG. 5 is a perspective view for explaining a manufacturing process of the heating roller shown in FIG.

FIG. 6 is a graph used to explain the rise time of the heating roller of the present invention.

FIG. 7 is a horizontal sectional view for explaining a modification of the heating roller shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heating roller 11 Cylindrical metal base 13 Cylindrical insulating layer 14 Cylindrical heat generating layer 15 Cylindrical insulating layer 16 Cylindrical heat insulating layer 17 Cylindrical spring body

Continued on front page F term (reference) 2H033 AA30 AA32 BA05 BB02 BB12 BB19 BB21 3J103 AA02 AA15 AA41 AA51 AA77 BA05 BA16 BA19 EA05 FA01 FA20 GA02 GA52 HA01 HA03 HA04 HA11 HA12 HA13 HA15 HA32 HA33 HA36 HA37 HA43 HA02 CE17 DA04 GA06

Claims (3)

[Claims] 1. A heating roller for fixing an unfixed toner image on recording paper in cooperation with a pressure roller, wherein the heating roller comprises a cylindrical metal substrate, and an inner peripheral surface of the cylindrical metal substrate. In the fixing device, a cylindrical heating layer is provided via a cylindrical insulating layer, and a cylindrical spring body is provided on the inner peripheral surface of the cylindrical heating layer via the cylindrical insulating layer. A fixing device, wherein a heat insulating layer is provided between the heat generating layer and the cylindrical spring. 2. The fixing device according to claim 1, wherein the heat insulating layer has a thickness of 2 mm or less. 3. The fixing device according to claim 1, wherein the cylindrical spring body is restrained from moving in the thrust direction of the cylindrical metal base.