JPH08166739A - Fixing device - Google Patents

Abstract

PURPOSE: To provide a fixing device which prevents cleaning rollers from abutting on a fixing roller and pressure roller at all times when the device is continuously used, prevents the cleaning rollers from being soiled and resulting in unsatisfactory cleaning and prevents the surfaces of the fixing roller and pressure roller from being scratched by foreign matters sticking to the surfaces of the cleaning rollers. CONSTITUTION: This device consists of the fixing roller 1 with a heater inside, the pressure roller 3 arranged in parallel to the fixing roller 1, and first and second cleaning rollers 4 and 5, respectively, used for cleaning the surfaces of both rollers, and is capable of making copies on both sides of a transfer sheet. The first cleaning roller 4 ad second cleaning roller 5 can be brought into contact with the fixing roller 1 and pressure roller 3, respectively, and separated therefrom. The second cleaning roller 5 is allowed to abut on the pressure roller 3 only when the pressure roller 3 is brought into pressure contact with the fixing roller 1 in order to fix an unfixed image on the back of the transfer sheet in both-side copying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art Conventionally, as a typical fixing device of this type, there is a fixing device as shown in FIG. 4, and this fixing device has a fixing roller 1 in which a heater 2 is arranged, and a fixing roller 1.
And a first and second cleaning rollers 4 and 5 for cleaning the surfaces of both rollers 1 and 3 for double-sided copying of transfer paper. 6 is an oil application member, and 7 is a scraper.

[0003]

However, in such a fixing device, the first and second cleaning rollers 4 and 5 are always in contact with the surfaces of the fixing roller 1 and the pressure roller 3, respectively, and such a state is brought about. Continuing to use, the first and second cleaning rollers 4, 5 gradually became dirty, and it became impossible to perform good cleaning, and further adhered to the surfaces of the first, second cleaning rollers 4, 5. There is a problem that the surface of the fixing roller 1 and the pressure roller 3 is scratched by foreign matter.

Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional fixing device and to keep the cleaning roller dirty without continuously contacting the fixing roller and the pressure roller during use. It does not become impossible to perform good cleaning, and moreover, the fixing roller, due to foreign matter adhering to the surface of the cleaning roller,
Another object of the present invention is to provide a fixing device that does not damage the surface of the pressure roller.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention according to claim 1 provides a fixing roller having a heater therein, and a fixing roller arranged in parallel with the fixing roller. In the fixing device which is configured to perform double-sided copying of the transfer paper, the fixing roller is provided with the above-mentioned pressure roller and the first and second cleaning rollers for cleaning the surfaces of the both rollers. The second cleaning roller is provided so as to be able to come into contact with and separate from the fixing roller and the pressure roller, and when the pressure roller is brought into pressure contact with the fixing roller in order to fix an unfixed image on the back surface of the transfer paper during double-sided copying. It is characterized in that it is only brought into contact with the pressure roller. According to a second aspect of the present invention, in the first aspect, the first and second cleaning rollers include a fixing roller and a pressing roller when at least the leading edge of the transfer paper contacts the nip of the fixing roller and the pressure roller. The nip portion of the pressure roller contacts the fixing roller and the pressure roller before reaching the nip between the first and second cleaning rollers and the fixing roller and the pressure roller. According to a third aspect of the invention, in the first aspect of the invention, the first and second cleaning rollers have a fixing roller at least when a trailing end of the transfer sheet is in contact with a nip of the fixing roller and the pressure roller. The nip portion of the pressure roller is in contact with the fixing roller and the pressure roller until it passes through the nip between the first and second cleaning rollers and the fixing roller and the pressure roller. Claim 4
In the invention described in claim 1, in the invention described in claim 1, when the first and second cleaning rollers are respectively separated from the fixing roller and the pressure roller, they are cleaned by another cleaning member. . According to a fifth aspect of the present invention, in the fourth aspect, the surface roughness of the cleaning member that cleans the surfaces of the first and second cleaning rollers is at least greater than the surface roughness of the first and second cleaning rollers. It is characterized by being coarse.

[0006]

According to the above-mentioned inventions of claims 1, 2 and 3, when fixing an unfixed image on the surface of the transfer paper by the fixing roller and the pressure roller at the time of single-sided copying or double-sided copying, In the first cleaning roller, at least the nip portion between the fixing roller and the pressure roller reaches the nip between the first cleaning roller and the fixing roller when the front end of the transfer paper contacts the nip between the fixing roller and the pressure roller. By the time, it contacts the fixing roller. Then, at least when the trailing edge of the transfer sheet comes into contact with the nip of the fixing roller, the nip portion of the fixing roller contacts the fixing roller until the nip portion of the fixing roller passes through the nip between the first cleaning roller and the fixing roller. Is cleaned, and when it is not fixed, it moves to the separated position. On the other hand, the second cleaning roller cleans the pressure roller by performing the same operation as the above-mentioned first cleaning roller only when fixing the unfixed image on the back surface of the transfer paper during double-sided copying. .

In the inventions of claims 4 and 5 as described above, when the first and second cleaning rollers are respectively separated from the fixing roller and the pressure roller, they are cleaned by another cleaning member. Since the surface roughness of (1) is at least rougher than the surface roughness of the first and second cleaning rollers, the foreign matter adhering to the first and second cleaning rollers is efficiently removed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In each of the embodiments shown in the drawings, the same parts as those of the conventional fixing device are designated by the same reference numerals, and the description thereof will be omitted. In the first embodiment of the present invention shown in FIGS. 1 and 2, the first and second cleaning rollers 4 and 5 are separated from the fixing roller 1 and the pressure roller 3 by a separated position shown by a solid line and a contact position shown by a dotted line. You can move between them and selectively position them. FIG. 2 shows a moving mechanism 10 for that purpose. The first and second cleaning rollers 4 and 5 are supported by a bearing 11, and the bearing 11 is provided with a support hole 13 provided in a bracket 12.
It is supported so as to be movable up and down and is constantly biased downward by a spring 14. The bracket 12 is attached to the operating rod 17 of the solenoid 16 attached to the machine frame 15 of the copying machine, and the guide pin 19 attached to the machine frame 15 is fitted in the long hole 18 provided in the bracket 12. .

In such a case, at the time of single-sided copying or double-sided copying, when fixing an unfixed image on the surface of the transfer paper P by the fixing roller 1 and the pressure roller 2, the first cleaning roller 4 is at least The nip portion between the fixing roller 1 and the pressure roller 2 when the front end of the transfer paper P contacts the nip between the fixing roller 1 and the pressure roller 2 reaches the nip between the first cleaning roller 4 and the fixing roller 1. until,
Contact the fixing roller 1. Then, at least the nip portion of the fixing roller 1 when the trailing edge of the transfer paper P contacts the nip of the fixing roller 1 contacts the fixing roller 1 until it passes through the nip between the first cleaning roller 4 and the fixing roller 1. The surface of the fixing roller 1 is cleaned by coming into contact therewith, and at the time of non-fixing, the fixing roller 1 is moved to the separated position shown by the solid line in FIG. As described above, when the first cleaning roller 4 is in contact with the fixing roller 1 as shown in FIG. 2, the solenoid 16 is off, the bracket 12 is lowered, and the first cleaning roller 4 is rotated by the spring 14. When the fixing roller 1 is pressed by the fixing roller 1, the solenoid 16 is turned on to raise the bracket 12 through the operating rod 17 when the fixing roller 1 is separated.

On the other hand, the second cleaning roller 5 performs the same operation as that of the first cleaning roller 4 described above only when fixing the unfixed image on the back surface of the transfer paper P during double-sided copying. 2 will be cleaned. However, it is the opposite of turning the solenoid 16 on and off,
Therefore, the raising and lowering of the bracket 12 is opposite to that of the first cleaning roller 4.

In the second embodiment shown in FIG. 3, when the first and second cleaning rollers 4 and 5 are separated from the fixing roller 1 and the pressure roller 2, the cleaning member 21 composed of another cleaning roller is used for cleaning. The structure is the same as that of the first embodiment except that it is different from the first embodiment. Therefore, the description of the similar parts will be omitted and the different parts will be mainly described. The cleaning member 21 includes the first and second cleaning rollers 4,
5 is impregnated with a dissolving agent such as alcohol or toluene capable of removing foreign matter adhering to 5, and its surface roughness is at least greater than that of the first and second cleaning rollers 4, 5. It's getting rough. In this embodiment, a gear 23 is attached to the rotary shaft 22 of the cleaning member 21, and the gear 23 is driven by a gear 26 attached to the fixing roller 1 and the pressure roller 3 via an idler 24 meshing with the gear 23. It has become. When the surfaces of the first and second cleaning rollers 4 and 5 are cleaned by the cleaning member 21 as described above, the roughness of the surfaces becomes larger than the roughness of the surfaces of the fixing roller 1 and the pressure roller 2. Therefore, the foreign matters attached to the surfaces of the fixing roller 1 and the pressure roller 2 are efficiently removed.

[0012]

The present invention is as described above, and the invention according to claim 1 is such that a fixing roller in which a heater is arranged, a pressure roller arranged in parallel with the fixing roller, In a fixing device including first and second cleaning rollers for cleaning the surfaces of both rollers, the first and second cleaning rollers are a fixing roller and a pressure roller. The second cleaning roller, which is provided so as to be able to come into contact with and separate from one another, comes into contact with the pressure roller only when the pressure roller is brought into pressure contact with the fixing roller in order to fix an unfixed image on the back surface of the transfer paper during duplex copying. So that even if you continue to use it,
The cleaning roller does not become dirty and it becomes impossible to perform good cleaning, and further, the surface of the fixing roller and the pressure roller is scratched by the foreign matter attached to the surface of the first and second cleaning rollers. There is no such a case, and there is an effect that the life can be extended. According to a second aspect of the present invention, in the first and second cleaning rollers, the first and second cleaning rollers have a fixing roller and a pressure roller in which at least a front end of the transfer paper is in contact with a nip of the fixing roller and the pressure roller. The nip portion of the contact roller contacts the fixing roller and the pressure roller by the time it reaches the nip between the first and second cleaning rollers and the fixing roller and the pressure roller, so that the foreign matter adhered to the surfaces of the fixing roller and the pressure roller. Can be cleaned immediately,
There is an effect that the surface of the fixing roller and the pressure roller is not scratched and the life can be extended. According to a third aspect of the present invention, in the first aspect of the invention, when the first and second cleaning rollers are separated from the fixing roller and the pressure roller, they are cleaned by another cleaning member, so that the first aspect is always applied. ，
2 The surface of the cleaning roller is kept clean,
Good cleaning can be performed even if it is used continuously, and the surface of the fixing roller and the pressure roller is not scratched by foreign matter adhering to the surfaces of the first and second cleaning rollers. There is an effect that can be extended. According to a fourth aspect of the present invention, in the first and second cleaning rollers, at least the rear end of the transfer sheet is in contact with the nip of the fixing roller and the pressure roller. The nip portion of the roller is in contact with the fixing roller and the pressure roller until it passes through the nip between the first and second cleaning rollers and the fixing roller and the pressure roller, and therefore adheres to the surface of the fixing roller and the pressure roller. It is possible to remove all the foreign substances, and it is possible to prolong the life without damaging the surfaces of the fixing roller and the pressure roller. According to a fifth aspect of the present invention, in the fourth aspect of the invention, the surface roughness of the cleaning member for cleaning the surfaces of the first and second cleaning rollers is
Since the surface roughness of at least the first and second cleaning rollers is at least rough, it is easy to remove foreign matter adhering to the surfaces of the first and second cleaning rollers, and the surfaces of the first and second cleaning rollers are always clean. Also, the surfaces of the pressure roller and the pressure roller are cleaned, and the surfaces of the fixing roller and the pressure roller are not scratched, and the life can be extended.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of the present invention.

FIG. 2 is a front view of a moving mechanism for the first and second cleaning rollers of the same.

FIG. 3 is a front view of a second embodiment of the present invention.

FIG. 4 is a front view of a conventional fixing device of the same type as the present invention.

[Explanation of symbols]

 1 Fixing Roller 2 Heater 3 Pressurizing Roller 4 First Cleaning Roller 5 Second Cleaning Roller 10 Moving Mechanism 11 Bearing 12 Bracket 13 Support Hole 14 Spring 15 Machine Frame 16 Solenoid 17 Actuating Rod 21 Cleaning Member 22 Rotating Shaft 23 Gear 24 Idler 26 Gear P Transfer paper

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yasuhiro Kodaira 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (5)

[Claims] 1. A fixing roller in which a heater is arranged, a pressure roller arranged in parallel with the fixing roller,
In a fixing device including first and second cleaning rollers for cleaning the surfaces of both rollers, the cleaning roller can be brought into contact with and separated from the fixing roller and the pressure roller. The second cleaning roller is provided on the pressure roller so as to fix the unfixed image on the back surface of the transfer paper during double-sided copying only when the pressure roller is pressed against the fixing roller. Characterizing fixing device. 2. The first and second cleaning rollers are such that at least the nip portion between the fixing roller and the pressure roller when the leading edge of the transfer paper contacts the nip between the fixing roller and the pressure roller. The fixing device according to claim 1, wherein the fixing device contacts the fixing roller and the pressure roller before reaching a nip between the fixing roller and the pressure roller. 3. The first and second cleaning rollers have at least a nip portion between the fixing roller and the pressure roller when at least a rear end of the transfer paper is in contact with the nip between the fixing roller and the pressure roller. The fixing device according to claim 1, wherein the fixing device is in contact with the fixing roller and the pressure roller until the nip between the roller and the fixing roller and the pressure roller is passed. 4. The fixing device according to claim 1, wherein when the first and second cleaning rollers are separated from the fixing roller and the pressure roller, they are cleaned by another cleaning member. 5. The fixing according to claim 4, wherein the surface roughness of the cleaning member for cleaning the surfaces of the first and second cleaning rollers is at least rougher than the surface roughness of the first and second cleaning rollers. apparatus.