JPH0634137B2 - Cleaning device - Google Patents

Description

The present invention relates to a cleaning device for removing foreign matter adhering to the surface of a moving body from the surface of the moving body. For example, fixing in a fixing device of a toner image forming apparatus such as an electrophotographic copying machine. The present invention relates to a cleaning device that can be used to remove and clean toner attached to a roller.

Conventionally, in a toner image forming apparatus such as an electrophotographic copying machine, in order to remove the toner adhering to the moving body to be cleaned,
A web cleaning device is used which removes toner from the surface of the moving body for cleaning by pressing a web-shaped cleaning member, which is a so-called cleaning web, that moves between the supply section and the winding section, onto the surface of the moving body. In particular, this type of web cleaning device is widely used for removing and cleaning the toner adhering to the fixing roller in the contact heating fixing device of the toner image forming apparatus.

FIG. 1 schematically shows a case where such a conventional web cleaning device is used for cleaning a fixing device. The illustrated fixing device has a pair of fixing rollers 1 and 2, and a recording sheet P having a toner image T formed on the surface thereof is fixed to the fixing rollers 1 and 2.
The toner image T is fixed on the recording sheet P by passing it between the two. In the figure, 3 and 3'are heaters, 4 is a temperature sensitive element for detecting the temperature of the roller surface, 5 is a separation claw for separating the recording sheet from the roller surface, and 6 is a cleaning object, that is, the surface of the fixing roller 1. 3 shows a cleaning device.

The cleaning device 6 includes a cleaning web _61, the cleaning web is fed from a supply 6 _5, are pressed against the fixing roller 1 by the elastic pressure members or elastic pressure roller 6 _3, O and around the winding section 6 ₂ To be 7
Is an entrance guide for guiding the recording sheet P between the fixing rollers. The arrow 9 indicates the rotation direction of the fixing roller, and the reference numeral 6'indicates the feeding direction of the cleaning web. The recording sheet P on which the image T is formed passes over the entrance guide 7, passes between the fixing rollers 1 and 2, and is ejected to the outside through the ejection roller.

In the above-described web cleaning device, the feed amount of the web per unit time is set so as to be able to completely perform the cleaning even when the image forming operation of the solid black original document is continuously performed. ing. Therefore, it is sufficient to send the required amount for each image forming operation (copying operation).

However, it can be considered that most of the ordinary manuscripts are those with many white backgrounds, and that the intermittent copying operation is overwhelmingly more frequent than the continuous copying operation.

Therefore, when copying such a normal document, if the web is fed at a speed that can be completely cleaned even when the solid black document copying operation is continuously performed as described above, a sufficient remaining capacity is left. The web will be rolled up. For example, in the case of copying an original document such as the specification of a patent and in the case of copying a solid black original document, the web feed speed required for complete cleaning is about 15 times higher in the solid black case. Is. This is a problem of the web replacement interval of the web cleaning device, that is, the life of the web cleaning device, and there is a difference of about 15 times the life depending on whether the web feed speed is adjusted to a normal document or a solid black document. However, when adjusting the web feed speed for normal manuscripts,
If an image with toner such as a solid black copy is taken, complete cleaning cannot be performed.

Since incomplete cleaning in this case, as shown in FIG. 2, the offset toner to accumulate in a nip portion formed between the fixing roller 1 by the pressing roller 6 ₃ is sent with adsorbed or attached to the web Since it becomes larger than the toner amount, it is gradually pushed into the nip end,
Furthermore, it means that it is pushed out from the nip portion. This free toner adheres to the surface of the fixing roller 1 and adheres to the recording sheet P held between the fixing roller 1 and the pressure roller 2 or once adheres to the pressure roller 2 to the recording sheet. The disadvantage is that it adheres to the back surface of P.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device capable of improving the drawbacks of the conventional cleaning device as described above, eliminating wasteful feeding of the web, and prolonging the replacement period of the web.

For such a purpose, the present invention effectively utilizes both sides of the web by pressing the first surface of the web, which is pressed against the fixing roller by the pressing member, against the surface of the fixing roller again. Since the adhesion is cleaned and the toner is rolled up while adhering the toner, the toner is not accumulated, so that the toner can be adhered to the recording sheet and a web cleaning device that can extend the life can be provided. is there.

That is, in the cleaning device according to the present invention, a cleaning web for cleaning the surface of the moving body is provided between the feed shaft and the winding shaft, and the first surface and the first surface are arranged in this order from the upstream side in the moving direction of the cleaning web. Both sides of the cleaning web are brought into contact with the moving body so that the second surface on the back side of the one surface comes into contact with the moving body, and the surface of the moving body is cleaned while the used cleaning web is wound around the winding shaft. In the cleaning device, the first surface moves in the same direction as the moving direction of the moving body surface, and the second surface is pressed against the moving body surface by a member different from the winding shaft and It is characterized by moving in a direction opposite to the moving direction.

Next, a reference example which is a premise of the present invention applied to a fixing device similar to that of FIG. 1 will be described with reference to FIG.

The cleaning device 8, which has been configured to remove toner and other foreign matter adhering on the fixing roller 1 by pressing a cleaning web ₈₁ made of nonwoven fabric or the like on the surface of the fixing roller 1, in Fig, 8 ₂ is a web supply unit, 8 ₃
The elastic pressing member for pressing a portion of the web to the surface of the fixing roller 1 (pressure roller) 8 ₅ shows a web winding section,
Web ₈₁ moves at very low speed in the direction indicated by the arrow.

Cleaning web ₈₁ is first pressed against the first surface to the surface of the fixing roller 1 with respect to the moving direction of the surface of the fixing roller 1, then is inverted, it is pressed against the second surface to the surface of the fixing roller The first surface can be moved in the same direction as the moving direction of the surface of the fixing roller 1, and the second surface can be moved in the opposite direction to the moving direction of the fixing roller.

In reference example shown in FIG. 3, the cleaning of the fixing roller 1 surface is carried out in part of the nip width n which is formed by a pressure roller 8 _3. When a completely clean web is used, toner adheres to the first surface of the web as shown in FIG. When a recording sheet having a relatively small amount of toner passes through the pair of fixing rollers, toner stains are subdued within the capacity of toner adsorption / adhesion of the web, and are conveyed together with the web while being held in that portion, and nip end n ₁ always comes to the new side of the web for the cleaning action as described above. However, when a recording sheet having a large amount of toner that exceeds the adsorption / adhesion capacity of the web passes continuously, the web cannot hold all the offset toner and is gradually pushed in the rotation direction of the fixing roller 1. , Will be extruded from the nip (Fig. 5). Most of this toner is held and conveyed by the web,
Some toner remains on the surface of the fixing roller and follows the rotation of the roller. For cleaning the toner is the second side of the cleaning web which is pressed against the surface of the fixing roller 1 by a web winding section 8 _5. That is, the winding section 8 ₅ is the web is wound in a direction in which the crosswise with respect to the pressure roller 8 _3, the second surface of the back of the first surface in pressure contact with the fixing roller 1 by the pressure roller 8 ₃ Is pressed against the fixing roller 1. Therefore, although the web of the winding portion is obtained by once passing between the pressure roller 8 ₃ and the fixing roller 1, the contact surface is always at the unused web surface. Further the rotation direction of the winding section 8 ₅ is the moving direction opposite to the direction of the surface of the fixing roller, the toner cleaned, since we involving progressively inward, the other or the toner adheres to, be or stain Without, you can wipe off the toner completely. The friction between the fixing roller in the contact surface of the winding section 8 _5, pulling force acts in the rotational direction of the fixing roller. Therefore, the winding unit _{8 5} always 1
It is necessary to be rotatable only in the direction (clockwise in the embodiment).

In the above reference example, the pressing roller 8 ₃ elastic used for pressing the first surface of the cleaning web ₈₁ to the surface of the fixing roller 1, the second surface of the cleaning web ₈₁ to the surface of the fixing roller 1 web winding section 8 for pressing ₅
Using itself. By thus pressing the first surface and the second surface against the surface of the fixing roller, the cleaning action is performed relatively well, but the foreign matter removed on the first surface is present between the wound webs. When the second surface is brought into contact with the fixing roller, contact unevenness may occur between the two.

The present invention performs the above-described cleaning without uneven contact, and an embodiment thereof is shown in FIGS. 6 (a) and 6 (b).

6 (b) is a web supply section ₈₂ and the web winding section 8 ₅
Apart from the above, examples in which pressure contact rollers 8 ₃ and 8 ₃ ′ are used are shown, and in the figure, 8 ₆ and 8 ₇ indicate guide rollers.

In this embodiment, while a web fed from a web supply section ₈₂ is moved to the surface in the same direction of the fixing roller 1, fixing the first surface by the pressure roller 8 ₃ roller 1
Of the fixing roller 1 is pressed against the surface of the fixing roller 1 and then the moving direction is reversed around the guide rollers 8 ₆ and 8 ₇ to move the second surface of the fixing roller 1 in the direction opposite to the moving direction of the surface of the fixing roller 1. It is pressed against the surface of the fixing roller by ₃ '. 6 (b) shows an example using a web supply section ₈₂ as the pressure roller. In other respects, what is shown in FIG. 6 (b) is the same as that shown in FIG. 6 (a).

An example of the mechanism for moving the cleaning web as described above is shown in FIG. The mechanism shown in FIG. 7 shows the web moving mechanism in the embodiment of the type shown in FIG. 6 (b). In Figure 7, 10 the axis 10 1 _(linked to the web supply section ₈₂₎ is rotating in the arrow direction by a motor. The web supply section ₈₂ is rotated by the rotation, it has turned out web ₈₁ little by little.

The web supply section ₈₂ is supported on a plate 12 which is swingably supported to the shaft 10 _1, have been pressed against the fixing roller 1 by a spring (not shown), the rotation of the rotation axis 10 ₁ It is transmitted by the gears 14 and 15. Thus, web supply section ₈₂ acts as a pressure roller, while feeding in the same direction as the moving direction of the web 8 ₁ fixing roller 1 surface, is pressed against the first surface to the surface of the fixing roller 1. The sent-out web 8 ₁ goes around the guide rollers 8 ₆ and 8 ₇ and is reversed in the moving direction, and is moved in the direction opposite to the moving direction of the surface of the fixing roller and the second surface thereof is pressed to the pressing roller 8 ₃ ′.
It is pressed against the surface of the fixing roller 1 by and wound on web take-up unit 8 _5.

Axis 11 of the web winding section _{8 5,} one-way mechanism 1 inside
It is rotationally driven by a lever 16 having 7 and is allowed to rotate only in the arrow direction by another one-way mechanism 18.
The lever 16 is constantly urged by the force of the spring 19 in the direction of arrow A. The cam 20 is mounted on the shaft 10 ₁ of the motor 10 at a position corresponding to the tip of the lever 16, and the rotation of the shaft 10 ₁ of the motor 10 causes
The cam 20 is rotated and the lever 16 repeats a swinging motion about the shaft 11. This swing motion is a one-way mechanism 1
It is transmitted to the shaft 11 via 7 and 18, and the shaft 11 is driven by the arrow C.
Rotates in the direction to rotate the web winding section 8 _5. Supply unit 8
When _{web 2} is fed to rotate is in tension between the winding section _{8. 5,} the rotation of the winding section 8 ₅ is suppressed, is suppressed even rocking movement of the lever 16 along with this, The lever 16 is stopped and held at a position away from the cam 20 against the force of the spring 19.

However, the lever 16 by the force of the tension loosens the spring 19 of the web between the web supply section ₈₂ and winding section 8 ₅ arrow A
And the one-way mechanism 17 rotates the shaft 11 in the direction of arrow C. Furthermore, the above-mentioned web tension is applied to the spring 19
Winding section 8 ₅ rotates by until greater than the force.
While the lever 16 repeats the swinging motion by the cam 20 while the motor 10 is rotating, the one-way mechanism 17 transmits only the rotation in the arrow C direction to the shaft 11. Further, by the action of the one-way mechanism 18, the frictional force of the web ₈₁ and the fixing roller 1, and rotates the take-up unit 8 _5, it is possible to prevent the web come loose.

As described above, in the present invention, the first surface of the web moves in the same direction as the moving direction of the moving body surface, and the second surface is pressed against the moving body surface by a member different from the winding shaft and By moving in the direction opposite to the moving direction of the moving body surface, the surface of the moving body to be cleaned can be reliably cleaned, and the web feed speed can be significantly slowed down, so the web replacement period can be extended. Is.

[Brief description of drawings]

FIG. 1 is a schematic view showing a conventional web cleaning device used for cleaning a fixing device, FIG. 2 is an explanatory view showing a cleaning state, and FIG. 3 is a reference of the present invention used for cleaning the fixing device. FIG. 4 is a schematic view showing an example, FIG. 4 and FIG. 5 are explanatory views showing a cleaning state according to the example of FIG. 3, and FIG. 6 (a) and (b) are schematic views showing an embodiment of the present invention. The figure is a perspective view showing an example of a mechanism for moving the cleaning web. 1, 2 ... Fixing roller, 3, 3 '... Heater 4 ... Temperature sensing element, 5 ... Separation claw 6 ... Cleaning device, 6 ₁ ... Cleaning web 6 ₂ ... Winding section, 6 ₃ ... … Pressing roller 6 ₅ …… Supply section, 7 …… Entry guide 8 …… Cleaning device, 8 ₁ …… Cleaning web 8 ₂ …… Web supply section, 8 ₃ …… Pressure contact roller 8 ₅ …… Web winding section, 8 ₆ , 8 ₇ ...... Guide roller 10 ...... Motor 10 ₁ ...... Motor shaft 11 ...... Shaft, 12 ...... Support plate 14,15 ...... Gear, 16 ...... Lever 17,18 ...... One way mechanism 19 ...... Spring, 20 ... Cam

Claims (1)

[Claims] 1. A cleaning web for cleaning the surface of a moving body is provided between a feed shaft and a winding shaft, and a first surface and this first surface are arranged in this order from the upstream side in the moving direction of the cleaning web. In a cleaning device for cleaning the surface of a moving body by contacting both sides of the cleaning web with the moving body so that the second surface on the back side contacts the moving body, and winding the used cleaning web around the winding shaft. , The first surface moves in the same direction as the moving direction of the moving body surface,
The cleaning device, wherein the second surface is pressed against the surface of the moving body by a member different from the winding shaft and moves in a direction opposite to the moving direction of the surface of the moving body.