JPH04186389A - Cleaning device for fixing device - Google Patents

Abstract

PURPOSE:To reduce contact resistance between a cleaning web and a fixing roller, and restrain damage to the fixing roller by extending a single continuous cleaning web around two web pressure rollers energized toward fixing rotary body, in such a way as to keep a different face in contact with respective pressure rollers. CONSTITUTION:There are provided two web pressure rollers 17 and 18 energized toward a fixing rotary body 8, and a single continuously cleaning web 16 is extended around the aforesaid web pressure rollers 17 and 18 in such a way as to keep a different face in contact therewith. The first contact face 27 of the web 16 is in contact with the second web pressure roller 18 and at this contact point, the cleaning web 16 has the second contact face 28 at the reverse side of the first contact face 27 in contact with the fixing roller 8. According to the aforesaid construction, cleaning capability can be improved, because of cleaning by both sides of the cleaning web 16 uniformly applied with a surface lubricant, without any damage to the surface of the fixing rotary body 8.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a fixing device that fixes a developer on a transfer material, and in particular, a fixing device that fixes a developer on a transfer material. The present invention relates to a cleaning device for a fixing device that performs cleaning by bringing it into contact with a fixing rotating body.

``Prior Art'' Conventionally, this type of fixing device has a fixing rotating body (referred to as a fixing roller) with a heater arranged inside to fix the developer onto the transfer paper, and an elastic layer around the outer periphery of the core metal. Usually, the transfer paper is fixed by rotating a pressure roller under pressure, passing the transfer paper through a nip between these rollers, and conveying the transfer paper while being heated and nipped. At this time, the developer that could not be fixed on the transfer paper is offset and adheres to the fixing roller. Methods for cleaning this offset developer include a method of contacting heat-resistant fibers containing a mold release agent (silicone oil), a method of contacting and rotating a brush-like cleaning roller, and a method of contacting heat-resistant fibers containing a mold release agent (silicone oil). Sheet-shaped heat-resistant paper (
There has been a web cleaning method in which one side of a cleaning web (hereinafter referred to as a cleaning web) is brought into contact with a fixing roller by an elastic sponge roller (hereinafter referred to as a web pressure roller). In particular, in the web cleaning method, as a method to improve the cleaning performance, cleaning is performed by bringing the back side of the cleaning web opposite to the side that comes into contact with the fixing roller into contact with the surface of the cleaning roller that is in contact with the fixing roller. C-Jitkai Showa 59-1041
No. 59) has been proposed.

[Problem to be solved by the invention] However, in recent years, there has been a need for further improvement in cleaning performance and high durability, and in order to improve the performance of the web cleaning method described above, it is necessary to However, the amount of cleaning web consumed is large, which increases running costs, and the cleaning device becomes larger, leading to an increase in equipment costs. For example, it is possible to obtain the same cleaning performance by cutting the cleaning web feed rate in half compared to the current cleaning web feed rate for single-sided cleaning, but maintenance of the cleaning roller is required, and the separation impregnated in the cleaning web is There is a drawback that the transfer rate of the silicone oil of the molding agent to the fixing roller is reduced.

The present invention has been made in view of the above, and an object of the present invention is to provide a cleaning device for a fixing device that can bring both sides of a cleaning web into direct contact with a fixing rotating body.

Touch the front and back sides of one cleaning web to the fixing roller,
Since the circumferential surface of the fixing roller moves, the web pressure roller that presses one side of the cleaning web against the fixing roller and the web pressure roller that presses the other side of the cleaning web against the fixing roller are connected to the fixing roller. They are arranged on the upstream and downstream sides in the direction of movement of the circumferential surface. However, when the cleaning web comes into contact with the fixing roller, most of the silicone oil as a release agent contained in the cleaning web is transferred to the fixing roller.

Therefore, the amount of release agent in the cleaning web that first performs the cleaning action is small (as a result, the contact resistance between the next cleaning web and the fixing roller increases, causing damage to the fixing roller. .

Another object of the present invention is to provide a cleaning device for a fixing device that is equipped with means for securing a release agent to the cleaning web after the first cleaning action in a cleaning device for a fixing device in which both surfaces of a cleaning web can be brought into contact with a fixing rotating body. The purpose is to provide the following.

"Means for Solving the Problems" The first aspect of the present invention is to bring the unfixed image side of the transfer material into contact with the
The cleaning device of the fixing device, which brings the cleaning web into contact with the fixing rotating body that performs fixing on the transfer material, is equipped with two web pressure rollers that are urged toward the fixing rotating body, and the cleaning web is connected to the two web pressure rollers continuously. A cleaning device for a fixing device is characterized in that a single cleaning web is wound around the cleaning web with different surfaces in contact with each other.

A second aspect of the present invention is that the first abutment surface for the fixing rotor closer to the winding side of the cleaning web is disposed on the upstream side with respect to the direction of movement around the fixing rotor, and the cleaning web is supplied. The first invention is characterized in that the second contact surface for the fixing rotor that is closer to the side is disposed on the downstream side of the first contact surface with respect to the rotational direction of the fixing rotor. This is a self-installed fixing device cleaning device.

The third aspect of the present invention is to contact the unfixed image side of the transfer material,
The cleaning device of the fixing device, which brings the cleaning web into contact with the fixing rotating body that performs fixing on the transfer material, is equipped with two web pressure rollers that are urged toward the fixing rotating body, and the cleaning web is connected to the two web pressure rollers continuously. A single cleaning web is wrapped around the cleaning web with its different sides in contact with each other,
A cleaning device for a fixing device, comprising means for bringing into contact an unactuated cleaning web and a cleaning web after the unactuated cleaning web is pressed by a pressure roller to first clean a fixing rotating body. It is.

"Embodiment" FIG. 1 is a front view showing the entire image forming apparatus according to the embodiment of the present invention, FIG. 2 is a schematic front view of the fixing device in FIG. 1,
FIG. 3 is a front view showing the state of cleaning by the cleaning web.

In FIG. 1, a photoreceptor 1 uniformly charged by a wide charger 2 is exposed to light by an exposure device 3, and the potential is attenuated to form a latent image, which is developed by a developer 4. Next, the image formed on the photoreceptor 1 by the transfer separation charger 5 is transferred onto a transfer paper P fed by a paper feeder, although the explanation will be omitted. The developer T remaining on the photoreceptor 1 is removed by a cleaning device 6. Further, the transfer paper P is sent to a prescribed position of the fixing roller 8 by the paper conveying device 7 and the paper guide 1o. Next, the transfer paper P is held and conveyed by a fixing roller 8 which is heated to a constant temperature by a heater 13 and a thermistor 11 and connected to a rotation drive device, and a pressure roller 9 which is in pressure contact with the fixing roller 8 and rotates as a result. The developer T is then fixed onto the transfer paper P. The developer T that could not be fixed at that time adheres to the fixing roller 8. The developer T adhering to the fixing roller 8 is cleaned by the cleaning device C.
removed. The transfer paper P that has passed between the fixing roller 8 and the pressure roller 9 is discharged to the outside of the machine by a pair of paper discharge rollers 20. Note that when the transfer paper P wraps around the fixing roller 8 after fixing, it is separated by the separation claw 12.

Next, the cleaning device C will be explained in detail.

In FIG. 2, the supply shaft 15 functions as a web feeding roller, and a cleaning web 16 is wound around it.

The cleaning web 16 fed out from the supply shaft 15 is wound around the web pressure roller 18 such that the cleaning web 16 passes between the second web pressure roller 18 and the fixing roller 8 . The web is wound between the web holding rollers 19 so as to intersect the line connecting the axes of the web pressure roller 18 and the web holding roller 19 (referred to as a sash-like wrapping). 19. , 21 (referred to as parallel wrapping), the cleaning web 16 is wound in a parallel manner around the web holding roller 21 and the second web pressure roller 17, and The cleaning web 16 passes between the fixing roller 8 and the web pressure roller 17, and is wound around the web winding shaft 14. A rotational drive device (not shown) is connected to the web take-up shaft 14, and the web take-up shaft 14 rotates for each copying operation or for every fixed number of copies.

In the above, the number of web holding rollers 19° 21 disposed between the two web pressing rollers 17° 18 can be one or three or more, but
．． 19 and 21. Cleaning web 1 between 21 and 17
The windings of 6 must be crossed in odd numbered places, and the remaining parts must be parallel. In this example, web pressure roller 1
The cleaning web 16 is hung only between the cleaning web 8 and the web holding roller 19 in a cross-legged manner.

Therefore, the first contact surface 27 (see FIG. 3) with the fixing roller 8, which is one side of the cleaning web 16 wound around the first web pressure roller 17, is the same as that of the first web pressure roller 17. , but not in contact with the web holding rollers 19 and 21,
The first contact surface 27 is in contact with the second web pressure roller 18 , and in this part, the cleaning web 16 has a second contact surface 28 on the back side of the first contact surface 27 that is in contact with the fixing roller 8 . come into contact with.

Although FIG. 4 shows the web pressure roller 17, the same applies to the web pressure roller 18. The shaft portions 22 provided at both ends of the web pressure roller 17 are rotatably attached to the tip of an arm 23, and the base of the arm 23 is attached to the frame of the fixing device (not shown) with a bin 24 to allow the arm 23 to rotate freely. Installation. One end of the web pressure roller tension spring 25 is locked near the tip of the arm 23, and the other end of the web pressure roller tension spring 25 is locked to a frame of a fixing device (not shown), and pulls the web pressure roller 17 in a direction to press it against the fixing roller. There is. The supply shaft 15 and the web holding rollers 19 and 21 are rotatably provided in immovable positions.

Next, the operations of the fixing device web and lean device C associated with the above fixing operation will be described. The fixing roller 8 is the transfer paper P
However, before the fixing roller 8 is operated, the web winding shaft 14 of the cleaning device rotates a small amount and winds up the cleaning web 16.

That is, when the web winding shaft 14 rotates, the cleaning web 16 wound around the first web pressure roller 17 moves in the direction of the arrow shown in the figure, and the first web pressure roller 17,
The web holding roller 21.19 rotates a small amount counterclockwise, the second web pressing roller 18 rotates a small amount clockwise, and the cleaning web 1, which is wound around the supply shaft 15,
6 is rolled out.

As shown in FIGS. 2 and 3, one side of the cleaning web 16 that is brought into contact with the fixing roller 8 by the first web pressure roller 17, that is, the first contact surface 27, is attached to the fixing roller 8↓. The developer T is cleaned, adheres to the cleaning web 16, and is wound around the winding shaft 14. At this time, the developer T that cannot be completely cleaned and remains on the fixing roller 8 is removed by the first cleaning web 16 that is brought into contact with the fixing roller 8 by the second web pressure roller 18 disposed on the downstream side. The contact surface 27 is completely cleaned by the second contact surface 28 on the back side and the cleaning web 16
It attaches to the body and is sent there. In addition, this second contact surface 28
The amount of developer T attached to the first contact surface 2 is small.
Since the cleaning is performed on the back side when viewed from the fixing roller 8, it may adversely affect the cleaning ability on the first contact surface 27, and the fixing roller 8 may
It will not cause any damage. Furthermore, silicone oil contained in the cleaning web 16 is transferred onto the fixing roller 8 at the second contact surface 28, contributing to prevention of developer offset.

In this embodiment, the cleaning web 16 that is pressed against the fixing roller 8 by the second web pressure roller 18 is
When the web passes through the pressure roller 18, most of the release agent silicone oil is lost. In order to prevent deterioration of the surface roughness of the fixing roller due to sliding friction with the cleaning web that has lost the release agent at the position of the first web pressure roller 17, the pressure contact of the second web pressure roller 18 is necessary. weaken the force. In the following example, the proportion of the mold release agent is actively measured.

FIG. 5 is a side view of another embodiment. Only the parts different from the previous embodiment will be explained. The center of the supply shaft 15 is located close to the straight line connecting the center of the second web pressure roller 18 and the center of the web holding roller 19, and the cleaning web 16 rotates clockwise.
is being wound. A second contact surface 28 appears on the outer periphery of the cleaning web 16 which is wound around the supply shaft 15 and has a cylindrical shape. The first contact surface 27 of the cleaning web 16 stretched between the holding rollers 19 and the contact portion 2
It is touching at 6.

When the web winding shaft 14 rotates counterclockwise to wind up the cleaning web 16, the cleaning web 16 wound around the supply shaft 15 is stretched between the second web pressing roller 18 and the web holding roller 19. cleaning web 16
The cleaning webs 16 move by the same amount and in the same direction at the contact portion 26, so these cleaning webs 16 contact each other and move without slipping.

Due to the rotation of the fixing roller 8, the second web pressure roller 1
When the cleaning web 16 wrapped around the fixing roller 8 rubs against the fixing roller 8 on the second contact surface 28, most of the silicone oil as the release agent moves from the cleaning web 16 to the fixing roller 8. However, due to the winding operation of the cleaning web 16 onto the web winding shaft 14, the cleaning web 16 in that portion is separated from the cleaning web 16 wound around the supply shaft 15 before it advances to the first web pressure roller 17. It comes into contact with the contact portion 26 of and receives the mold release agent. In this contact portion 26, one side of the outer side of the cleaning web 16 wound around the supply shaft 15, that is, the second contact surface 2
8, the same cleaning web 16 moves to the abutting portion 26 and comes into contact with the other side, that is, the first abutting surface 27. Since the feed speed of the cleaning web 16 is slow and the contact portion 26 is long, the cleaning web 16 with a large amount of release agent wound around the supply shaft 15 and the second web pressure roller 18 press the eight fixing rollers. The fixing roller 8 contacts the cleaning web 16 in which the release agent has been reduced for a long time at the front and back surfaces of the cleaning web 16, that is, the first and second contact surfaces 27 and 28. The amount of release agent in the cleaning web 16 becomes balanced. As a result, the amount of release agent on the cleaning web 16 that comes into contact with the fixing roller 8 by the second web pressure roller 18 is reduced before cleaning is performed, and
The first contact surface 27 of the cleaning web 16, which is pressed against the fixing roller 8 by the web pressure roller 17 that has received the release agent at the contact portion 26, contacts the fixing roller 8, and the amount of release agent is Compensated.

Therefore, even on the first contact surface 27, the silicone oil as the release agent transfers from the cleaning web 16 onto the fixing roller 8, and the contact resistance between the cleaning web 16 and the fixing roller 8 does not increase, so the fixing No damage is caused to the surface of the roller 8.

"Other Embodiments" FIG. 6 is a schematic diagram of a fixing device showing another embodiment, in which a cleaning web 16 wound around a supply shaft 15 is not shown, but is similar to the support for a web pressure roller, for example. The cleaning web 16 is first wound around the web mutual pressure roller 29 which is urged into contact with the web holding roller 19 by an elastic member, and then wound around the supply shaft 15 again.
The cleaning web 16 is wrapped around the outer periphery of the cleaning web 16 , is wrapped around the second web pressure roller 18 so that the second contact surface 28 is in contact with the fixing roller 8 , and is cleaned by the second contact surface 28 . The first contact surface 27 of the web mutual pressure roller 29
The second contact surface 28 is sandwiched between the roller 29 and the web holding roller 19 and comes into contact with the fresh surface of the cleaning web 16, so that the second contact surface 28 contacts the first surface of the used cleaning web 16. After moving to the contact surface 27 side and being impregnated, the web is sent out to the first web pressing roller 17. Also at the first contact surface 27 at the position of the first web pressure roller 17, the cleaning web 16
Since the cleaning web 16 contains silicone oil, the fixing roller 8 can be cleaned without increasing the contact resistance between the cleaning web 16 and the fixing roller 8, and the fixing roller 8 will not be damaged. Further, if the web mutual pressure roller 29 is made of a roller-shaped elastic material, the first contact surface 2
It is also possible to further improve the transfer rate of silicone oil to the 7 side.

[Effects of the Invention] As explained above, the present invention uses both sides of one continuous cleaning web to simultaneously clean the stationary rotating body at two locations, so the cleaning effect is significantly improved6. Since the moving speed of the cleaning web can be reduced, the life of the cleaning web can be significantly extended.

Furthermore, the cleaning web is brought into contact with the upstream side of the fixing rotor with respect to the moving direction of the circumferential surface of the fixing rotor, with the side of the cleaning web near the take-up shaft
By bringing the back side into contact with the fixing rotor on the downstream side, the transfer rate of the release agent to the fixing rotor, that is, the amount of release agent transferred to the fixing rotor, and the cleaning web can be adjusted. There is no reduction in the ratio of the remaining female type agent.

Furthermore, since a means is provided for bringing the unacted cleaning web into contact with the cleaning web that first contacted the fixing rotor, the cleaning web at the two contact points with the fixing rotor contains a release agent. Since the contact resistance with the fixing rotor does not increase, the surface of the fixing rotor can be cleaned by cleaning with both sides of the cleaning web evenly distributed with release agent, without damaging the surface of the fixing rotor. Performance can be improved. Further, since no new release agent application means is required, the cost does not increase.

[Brief explanation of drawings]

1 is a front view schematically showing an entire image forming apparatus embodying the present invention, FIG. 2 is a front view illustrating a fixing device embodying the present invention, and FIG. 3 is a front view showing a state of cleaning by a cleaning web. FIG. 4 is a front view of a pressurizing device for a web pressurizing roller, and FIGS. 5 and 6 are front views of other embodiments/examples, respectively. 8. Fixing roller 14. Winding shaft 15. Supply shaft 16. Web 17. First web pressure roller
18. Second web pressure roller 29. Web mutual pressure roller P. Transfer paper T. Developer. Patent applicant Canon Co., Ltd.

Claims (1)

[Scope of Claims] 1. In a cleaning device of a fixing device in which a cleaning web is in contact with a fixing rotary body that performs transfer onto the transfer material with the unfixed image side of the transfer material in contact with the cleaning web, the cleaning web is urged toward the fixing rotary body. 1. A cleaning device for a fixing device, comprising two web pressure rollers, and a continuous cleaning web is wound around the two web pressure rollers with different surfaces in contact with each other. 2. The first abutment surface for the fixing rotor closer to the cleaning web winding side is arranged on the upstream side with respect to the direction of movement around the fixing rotor, and the first contact surface for the fixing rotor closer to the cleaning web supply side The second contact surface with respect to the rotating body
2. The cleaning device for a fixing device according to claim 1, wherein the cleaning device is disposed on the downstream side of the abutting surface of the fixing rotor in the rotational direction of the fixing rotor. 3. In the cleaning device of the fixing device, in which the unfixed image side of the transfer material is in contact with the cleaning web, which is in contact with the fixing rotary body that performs fixing on the transfer material, two webs are urged toward the fixing rotary body. A continuous cleaning web is wound around two web pressure rollers with different surfaces in contact with each other, and the unworked cleaning web and the unworked cleaning web are pressed by the pressure roller. 2. The cleaning device for a fixing device according to claim 1, further comprising means for bringing a cleaning web into contact with the fixing rotating body after first cleaning it.