JP2000047507A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve saving of energy and shortening of a start-up time, in a fixing device of a heat-roller system. SOLUTION: A pair of pressure rollers 1 and 2 having roller surfaces made of a material that absorbs infrared rays are provided, and as infrared-rays irradiation devices 31 for irradiating infrared rays to the roller surfaces of the pressure rollers 1 and 2, ones which are each composed of a halogen lamp heater 32 and a reflecting plate (ellipsoidal mirror) 33 are provided. Part of the infrared rays from the heaters 32 are directly emitted to the roller surfaces and other parts are reflected from the reflecting plates 33 and thereafter emitted to the roller surfaces, and they are absorbed by the pressure roller surfaces and converted into heat. Because the pressure rollers 1 and 2 are heated from the surfaces, the temperatures of the roller surfaces are raised to fixing temperatures without heating the insides of the rollers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat roller type fixing device used in an electrophotographic recording device.

[0002]

2. Description of the Related Art Conventionally, as a fixing device of an electrophotographic apparatus, a fixing roller (pressure roller) having a built-in heater and a pressure roller pressed against the fixing roller are rotated while rotating the pressure roller. Material (paper) in the nip
The fixing device is of a type in which an unfixed toner image (image forming substance) on a recording material is melted and fixed by passing the toner image through the recording material.

In such a fixing device, it is required that the rising time, that is, the time until the temperature rises to a predetermined fixing temperature, is short and that the fixing operation can be performed with energy saving.

Meanwhile, as for the heat roller type fixing device, for example, (1) Japanese Patent Publication No. 2016384 discloses a method in which a heat source is provided in the fixing roller, the fixing roller is heated by the heat, and the fixing roller itself has a wavelength of 2 μm. A device that emits far infrared rays as described above is disclosed. Also, (2) Japanese Patent Application Laid-Open No. 7-140821 describes a fixing device having a structure in which a fixing roller is constituted by a ceramic heater that emits far-infrared rays, and the periphery of the fixing roller is surrounded by a reflector. Further, (3) Japanese Patent Application Laid-Open No. 6-161311 proposes a means for fixing a toner in a non-contact manner by heating, in which a spectral characteristic of a radiation heating source is specified.

[0005]

However, in the fixing device disclosed in the above patent publications (1) and (2), in order to emit far-infrared rays, it is necessary to heat the entire roller having a large heat capacity. There is a problem that the rise time becomes long. Further, the fixing device of the above (3) has a problem that the fixing property is low because the toner is fixed by non-contact heating, and it is necessary to increase the heating temperature to increase the fixing property. There was a problem of using the energy of.

The present invention solves the above-mentioned problems of the prior art, and has both the advantages of a non-contact heating system in which the rise time is short and the power consumption is small, and the advantages of fixing by pressurization in which the fixability is good. It is an object to provide a fixing device.

That is, an object of the invention according to claim 1 is as follows.
It is an object of the present invention to heat the pressure roller from the surface to bring the surface of the roller to a temperature at which the roller can be fixed without heating the entire roller, thereby realizing energy saving of the fixing device and shortening of a rise time.

An object of the present invention is to heat the recording material and the image forming material before the pressure roller, thereby realizing energy saving of the fixing device and shortening of the rise time.

An object of the invention according to claim 3 is to realize energy saving of a fixing device and shortening of a rise time by heating a recording material and an image forming material in the vicinity of a nip portion of a pressure roller. .

[0010]

To achieve the above object, a fixing device according to the first aspect of the present invention (FIG. 1) comprises a pair of pressure rollers 1 and 2 at least whose roller surfaces are formed of a material that absorbs infrared rays. And an infrared irradiation device 31 for irradiating at least one roller surface of these pressure rollers with infrared light.
And an infrared source 32 and an infrared reflecting member 33.

The fixing device according to the present invention (FIG. 2) includes a pair of pressure rollers 11, 12, a recording material 41 immediately before these pressure rollers, and an image forming material 42 on the recording material.
As an infrared irradiation device 31 for irradiating infrared rays to
An infrared source 32 and an infrared reflecting member 33.

A fixing device (FIG. 3) according to a third aspect of the present invention includes a pair of pressure rollers 21 and 22 each having a roller surface formed of a material that absorbs infrared rays and generates heat, and the pressing roller from the upstream side of a fixing process. Near the nip 23 between the pressure rollers, the recording material 41
Further, as an infrared irradiation device 31 for heating the image forming substance 42 on the recording material, a device including an infrared source 32 and an infrared reflection member 33 is provided.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 The fixing device shown in FIG. 1 is according to claim 1, and the surface layers 1a and 2a of the pressure rollers 1 and 2 are formed of a material having a property of absorbing infrared rays. In this fixing device, part of the infrared light from the infrared source (heater) 32 is directly on the surface of the pressure roller, and part of the infrared light is reflected by the infrared reflecting member (reflecting plate) 3.
After being reflected at 3, the surface of the pressure roller is irradiated, and is absorbed by these pressure roller surfaces and converted into heat. Reflector 33
Is for condensing infrared rays radiated in directions other than the pressure roller onto the pressure roller. Since these pressure rollers are heated from the surface, the roller surface temperature can be set to a temperature required for fixing without heating the inside of the roller, so that the rise time is shortened and energy saving is achieved. Fixing can be performed.

The recording material 41 on which the image forming material 42 is placed is passed through the nip portion 3 between these pressure rollers, so that the image forming material can be fixed on the recording material 41. Here, the recording material is a base material that carries the formed image, and is generally paper. The image forming substance is a material that forms an image on a recording material, and is a toner in the case of an electrophotographic method as in the present invention.

It is more preferable to provide a layer made of a material having high heat insulating properties as a lower layer of the roller surface layers 1a and 2a so that heat on the roller surface does not escape into the roller. Examples of the heat insulating material include a rubber material (foamed rubber such as foamed silicone rubber) which is foamed to contain air. Further, in order to enhance the infrared absorption efficiency of the roller surface, carbon black may be dispersed in the material of the surface layer. Further, the roller surface is made of a material having good releasability so that the toner does not adhere to the roller surface during fixing, for example, a fluorine-based material such as PTFE (polytetrafluoroethylene) or ETFE (ethylene-tetrafluoroethylene copolymer). It may be formed. In FIG. 1, a combination of a heater 32 and a reflection plate 33 is provided so as to heat both pressure rollers so that simultaneous fixing of two-sided copying can be performed.
When fixing is performed one by one, one combination of the heater 32 and the reflection plate 33 may be provided.

The shape of the reflection plate 33 may be an ellipsoid or a paraboloid as shown in FIG. Examples of the infrared light source 32 include a ceramic heater and a halogen lamp heater. Halogen lamp heaters are preferred because they have a particularly short rise time.

According to the configuration shown in FIG. 1, since it is not necessary to heat the entire pressure roller, the rise time is determined by the rise time of the heater. Therefore, the use of a fast rising heater such as a halogen lamp heater can shorten the rising time of the fixing device. Also,
Since there is no need to heat the entire roller, power consumption is also reduced.

Embodiment 2 FIG. 2 shows the structure of a fixing device according to a second embodiment. This fixing device is characterized in that the paper 41 and the toner 42 are heated on the front side of the pressure rollers 11 and 12 by infrared rays emitted from the infrared ray source 32.
Since the paper 41 and the toner 42 are directly heated, it is possible to efficiently heat without waste of heat. As in FIG. 1, a reflection plate 33 is provided to concentrate infrared light from the infrared light source 32 on paper and toner. If the wavelength of the infrared ray and the absorption wavelength of the toner are matched, heating can be performed more efficiently. In FIG. 2, both sides of the paper are simultaneously heated so that double-sided copying can be performed simultaneously. However, in the case of fixing one side at a time, the heater 32 and the reflection plate 33 need only be one side.

Third Embodiment FIG. 3 shows the structure of a fixing device according to a third embodiment. The fixing device is characterized in that the vicinity of the nip 23 between the pressure rollers 21 and 22 and the paper 41 and the toner 42 are heated by infrared rays. The paper 41 and the toner 42 are efficiently heated by directly irradiating the infrared rays to the paper 41 and the roller surface is also heated at the same time, so that a decrease in the toner temperature in the nip 23 can be suppressed. Also in this case, two combinations of the heater 32 and the reflection plate 33 are provided so as to enable simultaneous fixing of double-sided copying. However, when fixing is performed on each side, only one combination is sufficient.

[0020]

Embodiment 1 (corresponding to claim 1) In the configuration of FIG. 4, a halogen lamp heater (100 V.times.500 W) is used as the heater 32, and an elliptical mirror (major axis 50 mm, minor axis 40 mm, focal length) is used as the reflector 33. 30m
m) was used. As shown in FIG. 5, the halogen lamp heater was installed at one focal position of the elliptical surface of the reflecting plate 33, and the other focal point was such that the distance d from the surface of the pressure roller was 5 mm inside. In FIG. 5, reference numeral 32a denotes an infrared ray.

The pressure rollers 1 and 2 have a diameter of 26 mm.
A 7 mm thick foamed silicone rubber with JIS hardness of 45 degrees is wound around the surface of the stainless steel cored bar, and the surface is 50 μm thick.
The ETFE film was wound. An unfixed image sample was prepared from a plain paper copying machine spirio 2210 (trade name, manufactured by Ricoh Co., Ltd.) from which the fixing unit was removed, and the sample was passed through the fixing device shown in FIG.
At this time, the rise time of the fixing device was within 10 seconds, and it was not necessary to heat the entire pressure roller.

Embodiment 2 (corresponding to claim 2) In the configuration of FIG. 6, a halogen lamp heater (100 V.times.700 W) is used as the heater 32, and an elliptical mirror (major axis 50 mm, minor axis 40 mm, focal length 30 m) is used as the reflector 33.
m) was used. Halogen lamp heater is installed at one of the focal points of the ellipsoid, paper and toner are 5mm more than the other focal point
It was installed to be inside. The same pressure roller as in Example 1 was used. Plain paper copier spiri2210
(Manufactured by Ricoh, trade name), the fixing device was removed, and the fixing device of FIG. 6 was assembled instead. When copying was performed by this apparatus, a copy having a good fixing state could be obtained.
In addition, the start-up time of the copier at this time is within 10 seconds, and since it is not necessary to heat the entire fixing roller, power consumption can be reduced as compared with the related art.

Embodiment 3 (corresponding to claim 3) In the configuration of FIG. 7, a halogen lamp heater (100 V.times.700 W) is used as the heater 32, and an elliptical mirror (long axis 86 mm, short axis 50 mm, focal length 70 m) is used as the reflector 33.
m) was used. The halogen lamp heater is installed at one of the focal points of the elliptical surface, and as shown in FIG.
The nip portion 23 was set so as to irradiate the vicinity.
The same rollers as those in Example 1 were used as these pressure rollers. The fixing device of FIG. 7 was assembled by removing the fixing device from a plain paper copying machine spiri4000 (trade name, manufactured by Ricoh). When copying was performed by this apparatus, a copy having a good fixing state could be obtained. In addition, the start-up time of the copier at this time is within 10 seconds, and in addition, since it is not necessary to heat the entire fixing roller, power consumption can be reduced as compared with the related art.

[0024]

As apparent from the above description, the following effects can be obtained according to the present invention. (1) The invention of claim 1 A pair of pressure rollers at least whose roller surfaces are formed of a material that absorbs infrared rays, and an infrared irradiation device for irradiating at least one roller surface of the pressure rollers with infrared rays. The fixing device is configured by including an infrared source and an infrared reflecting member, and the pressure roller is heated from its surface.Therefore, the temperature of the roller surface can be fixed without heating the entire roller. As a result, energy saving of the fixing device and shortening of the rise time can be realized.

(2) A pair of pressure rollers, and an infrared irradiation device for irradiating a recording material and an image forming material on the recording material with infrared light immediately before the pressure roller, The fixing device is composed of an infrared source and an infrared reflecting member, and the recording material and the image forming substance are heated in front of the pressure roller.This saves energy and shortens the startup time of the fixing device. realizable.

(3) The third aspect of the invention: a pair of pressure rollers having roller surfaces formed of a material that absorbs infrared rays and generates heat; A fixing device is configured by providing an infrared irradiation device for heating the recording material and the image forming material on the recording material, the device including an infrared source and an infrared reflection member. Since the recording material and the image forming substance are heated,
Energy saving of the fixing device and shortening of the rise time can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of Embodiment 1 of the present invention.

FIG. 2 is an explanatory sectional view of a second embodiment.

FIG. 3 is an explanatory sectional view of a third embodiment.

FIG. 4 is an explanatory sectional view of Embodiment 1 of the present invention.

FIG. 5 is a partially enlarged view of FIG. 4;

FIG. 6 is an explanatory sectional view of a second embodiment.

FIG. 7 is an explanatory sectional view of a third embodiment.

[Explanation of symbols]

 1, 2 pressure roller 1a, 2a surface layer 3 nip portion 11, 12 pressure roller 21, 22 pressure roller 21a, 22a surface layer 23 nip portion 31 infrared irradiation device 32 infrared source (heater) 32a infrared 33 infrared reflecting member (Reflector) 41 Recording material (paper) 42 Image forming substance (toner)

Claims (3)

[Claims] 1. A pair of pressure rollers, at least a roller surface of which is formed of a material that absorbs infrared light, and an infrared light source for irradiating at least one roller surface of the pressure roller with infrared light. A fixing device comprising an infrared reflecting member. 2. An infrared source and an infrared reflecting member as an infrared irradiation device for irradiating a recording material and an image forming material on the recording material immediately before the pressure roller with a pair of pressure rollers. A fixing device comprising: a fixing device; 3. A pair of pressure rollers each having a roller surface formed of a material that absorbs infrared rays and generates heat, a portion near a nip between the pressure rollers from an upstream side of a fixing process, a recording material, and the recording material. A fixing device provided with an infrared irradiation device for heating an image forming substance on a material, the device including an infrared source and an infrared reflection member.