JPS60104983A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent the generation of paper wrinkles at the fixing time by constituting the surface of a pressing roller contacting with a heat roller by a permeable material and providing the outside and inside of the pressing roller with permeability. CONSTITUTION:The pressing roller 11 contacting with the heat roller 1 is constituted by laminating an elastic layer 13 and a permeable material layer 14 successively around a roller base material 12. Many vent holes 15 are formed on the whole periphery of the laminated part of the elastic layer 13 and the base material 12. The permeable material layer 14 is constituted by glass fiber cloth or the like. Although steam generated at the fixing time is concentrated into the rush side of recording paper 9, the steam is penetrated into the permeable material layer 14 and guided to the inside of the pressing roller through the vent holes 15. Consequently, paper wrinkles to be generated when the recording paper 9 absorbs the moisture, expands and rushes into a nip part 10 at the fixing time is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention compresses and heats unfixed developer (toner powder) on an image carrier (recording paper) in an information recording device such as a facsimile, copying machine, or printer. The present invention relates to a heat compression type fixing device for fixing.

Conventional Structures and Problems With the remarkable development of information recording devices in recent years, the demand for improved image quality of recorded matter has increased, and it has become necessary to fix stable and high-quality toner powder. A conventional fixing device will be described below with reference to the drawings. FIG. 1 is a side sectional view of a conventional fixing device. Reference numeral 1 denotes a heating roller, which is composed of a surface treatment layer 2, a heating roller base material 3, and a heater 4.

Here, the heating roller base material 3 is generally made of a metal material such as aluminum. The surface treatment layer 2 is formed by coating the heating roller base material 3 with a material having good releasability, such as a fluorinated resin, in order to improve the releasability from the toner powder 5. The heater 4 is a heat source for heating the heating port 1, and is maintained at a predetermined temperature by a control circuit. Reference numeral 6 denotes a pressure roller, which is made up of a pressure roller base material 7 and an elastic body layer 8, and the elastic body layer 8 is generally made of heat-resistant silicone rubber or the like. The heating roller 1 and the pressure roller 6 are in contact with each other with a predetermined pressure applied between their axes by a spring or the like. The heating roller 1 is driven and rotated at a predetermined speed by an external drive source (not shown), and the pressure roller 6 rotates in the opposite direction to that of the heating roller 1 due to the frictional force caused by contact with the heating roller 1. driven by In this state, the recording paper 9 holding the toner powder 5 is placed between the contact portion between the heating roller 1 and the pressure roller 6 [hereinafter referred to as nip portion 10].
When inserted into the nip 1, the toner powder 5 is inserted into the nip 1.
While passing through zero, it is melted by pressure and heat and fixed on the recording paper 9.

The conventional fixing device as described above has a relatively simple structure and is generally widely adopted.
0, the water contained in the recording paper 9 becomes water vapor due to heating, enters the gap in the nip 10, and is released to the outside.
The unfixed portion of the recording paper 9 that has been taken out and before entering the nip section 10 absorbs this water vapor and enters the nip section 10 in an expanded state, so that paper wrinkles are likely to occur in the recording paper after fixing. There is a problem with this.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional art.The present invention is aimed at solving the above-mentioned drawbacks of the conventional art. Image j111 that is turned into water vapor and discharged due to heating when passing through the pressure contact part
00-containing moisture is discharged and covered inside the second roller through the air-permeable material 1 on the surface of the second roller.J: The unfixed portion of the image carrier absorbs the water vapor and is expanded in a state of pressure contact. To provide a fixing device which prevents the occurrence of paper wrinkles due to intrusion into a portion of the image, and which does not cause paper wrinkles during fixing. 1. Structure of the Invention In order to achieve the above object, the fixing device of the present invention comprises a first O-ra and a second O-ra that are in pressure contact with each other at their outer peripheries. With one side heated, an image carrier holding a developer such as toner powder is passed through the pressure contact portion of the pair of rollers, and the developer is heated and compressed to melt and fix on the image carrier. , and when the first roller is the roller that comes into pressure contact with the developer holding surface of the image carrier, the surface portion of the second roller is made of an air-permeable material, and the surface of the second roller is made of an air-permeable material. The second roller is configured to have air permeability on the outside and inside.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 2 shows a side sectional view of the fixing device in the first embodiment of the present invention. In FIG. 2, the same member as the conventional example shown in FIG. The pressurizing roller 11, which serves as a roller, is also constructed by laminating an elastic layer 13 and a breathable material II layer 14 in order around a material 12. FIG. 3 shows an enlarged view of the main parts of the pressure roller 11.
Small ventilation holes 1 for ventilation from 4 to the inside of the pressure roller
5 over the entire outer circumference. Breathable material layer 1
4 is composed of glass fiber assembly A [I, etc.

Next, the air permeability when the recording paper 9 passes through the so-called nip section 10, which is the pressure contact section between the heating roller 1 and the pressure roller 11.

In order to clarify the effect of the moon r4 layer 14, Fig. 4 a, b
The operation in comparison with the conventional example will be explained below. In FIG. 4, a shows the case of the conventional example, and b shows the case of the embodiment according to the present invention.
9 is in the middle of passing through the nip section 10, and ■ shows the state after the recording paper 9 has passed through the nip section 10. In cases a and b, when the recording paper 9 enters the nip section 10, the moisture contained in the recording paper 9 is heated and compressed within the nip section 10 and becomes water vapor and is discharged outside the nip section 10. be done. The discharge state of water vapor is shown in FIGS. 5a and 5b, where a shows the case of the conventional example and b shows the case of the embodiment according to the present invention. While the recording paper 9 is passing through the nip portion 10, water vapor is mainly discharged in four directions: A, [1, C, and 2], as shown in a. b shows how water vapor that has entered the breathable material layer 14 is guided into the pressure roller 11 through the vent 15, thereby reducing the amount of water vapor discharged from the gap in the nip portion 10. In this case, the water vapor introduced into the pressure roller 11 is transferred to the pressure roller 11 from the end of the pressure roller 11.
It is designed to be discharged to the outside. Therefore, in the case of the embodiment according to the present invention, before the recording paper 9 enters the nip portion 10, the degree to which the recording paper 9 absorbs water vapor generated from a part of the recording paper 9 that has already entered, moisturizes, and expands is extremely small. As shown in FIG. 4 (■), in the case of the conventional example a, the recording paper 9 absorbs water vapor and expands just before the nip 10, causing the paper surface to wave and rush into the nip 10. According to the embodiment of the present invention shown in b, the recording paper 9 does not absorb moisture or expand, and the paper wrinkles as shown in (■) in b occur. No fixed number 1 is given 19. Here, the function of the ventilation layer 14 will be further explained. The vent hole 15 of the pressure roller 11 is provided with a predetermined density 'c-RQ' around the pressure roller 11 in order to allow movement of air between the outer circumference of the elastic fiber Fi 13 and the inside of the roller base material 12.
I) However, it is difficult to arrange the pressure rollers 11 at high density because of the need to ensure strength and maintain elasticity of the pressure rollers 11. Therefore, if the elastic layer 13 is directly pressed against the first roller [heating roller 1] without using the breathable material layer 14, the water vapor near the opening t'' of the vent hole 15
Although 59 people are placed inside the roller 11 through the application, the recording material 419 comes into direct pressure contact with the elastic layer 13 in areas other than the opening, and the water vapor with no escape is discharged through the gap J in the nip 10. This can cause paper wrinkles. Air-permeable material layer 141J At this nip portion 10, recording paper 9 and elastic layer 13
Leave space between the two so that they do not touch each other closely, and record the
9 is introduced over the entire surface and is sent to the vent 15.

FIG. 6 shows a side sectional view of a fixing device according to another embodiment of the present invention. The difference in FIG. 6 from the first embodiment is that instead of the pressure roller 11, it is supported so as to be wound around two shafts 16 and 17 and has approximately the same width as the heating roller 1. An endless belt 18 is provided, and the endless belt 18 is made of air-permeable and heat-resistant glass fiber navy blue cloth or Conex fiber cloth. It is wound in conjunction with the rotation of step 1. Record 1119 holding toner powder 5 is heated roller 1
The water vapor generated when passing through the pressure contact part [nip part 19] of the endless belt 18 is discharged inside the endless belt 18 through the endless belt 18 made of a breathable material. The amount of water vapor discharged from the gap is reduced, and the same effect as in the first embodiment is obtained by 1q.

Effects of the Invention As described above, the present invention comprises a first roller and a second roller that press against each other on their outer peripheries. 11 passes through an image carrier holding a developer such as toner powder in a section 11, and heats and compresses the developer to melt and fix it on the image carrier 11, and the developing agent of the image carrier The lifting platform has a roller that comes into pressure contact with the agent holding surface as the first 0-ra, and the surface of the second 1-ra is made of a breathable layer, and the second 0-ra is formed through the surface. 1- Ventilation on the outside and inside of the rack 1
! 1, the image carrier (
When the recording paper (recording paper) passes through the pressure contact portion of the pair of rollers, the moisture contained therein, which is turned into water vapor by heating and discharged from the image bearing member, is discharged to the inside of the second roller through the air-permeable partition. It is possible to realize a fixing device that prevents paper wrinkles caused by the unfixed portion of the image bearing member absorbing the water vapor, expanding, and entering the pressure contact portion of the conventional image bearing member.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional fixing device, FIG. 2 is a side sectional view of the fixing device according to 1) in the first embodiment of the present invention, and FIG. 3 is a main part of the pressure roller shown in FIG. 2. Enlarged view, Figures 4a, b and 5
Figures a and b are explanatory diagrams comparing the effects of the conventional example and the first embodiment of the present invention, and Fig. 6 is a side sectional view of a fixing device in another embodiment of the invention. 1...Heating roller, 2...Surface treatment 1ff! layer, 3・
... Heating roller base material, 4 ... Heater, 5 ... I-no-powder, 9 ... Recording paper, 10 ... Nip part, 11
... Pressure [I-ra, 12... Roller base material, 13...
- Elastic body layer, 14... Breathable material layer, 15... Ventilation [1, 16, 17... Shaft, 18... E [Endless bells 1 to . 19... Nip Department Agent Yoshihiro Morimoto Figure f Figure 3 1ri Figure 4 Ca) Figure 5

Claims (1)

[Claims] 1. Toner powder is applied to the pressure contact portion of the roller pair in a state where at least one of the roller pairs consisting of a first roller and a second roller that are in pressure contact with each other on their outer peripheries is heated. The developer is passed through an image carrier holding a developer such as the like, and the developer is heated and compressed to be melted and fixed on the image loss carrier, and the developer holding surface of the image carrier and When the roller to be pressed is the 10th roller, the surface of the second roller is made of a breathable material, so that the surface is breathable to the outside and inside of the second roller. Configured fixing device. 2. The fixing device according to claim 1, wherein the second roller includes two or more rollers and an endless bell supported so as to be freely wound around these rollers. 3. The constant @ device according to claim 1 or 2, wherein the breathable material is made of glass 1311 cloth.