JPS5990875A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent inconvenience due to a surplus liquid by making a control layer of a material by which a passing property of a liquid is increased when it is elongated slide-contact with a rotating body, supplying an offset preventive liquid of a proper quantity at the time of an operation, and stopping the supply when the operation is ended. CONSTITUTION:A control layer 10 is constituted of a porous elastic body whose passing property is increased when it is elongated, and slide-contacts with a roll 1. When the roll 1 is rotated, the layer 10 is elongated by DELTAl in the rotating direction by frictional force against the roll 1, and is restored when the rotation is stopped. Accordingly, at the time of the fixing operation, the layer 10 supplies oil of a proper quantity to the roll 1, but when the fixing operation is ended and the rotation of the roll 1 is stopped, the layer 10 is restored and reduces or eliminates the oil passing quantity. Accordingly, it can be prevented that surplus oil adheres onto the fixing roll and paper is contaminated after the fixation is ended.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing device that carries out a fixing process by conveying a toner image support material between a pair of rollers. Regarding.

In the above-mentioned fixing device, so-called coating 7150-La is sometimes used to apply anti-offset liquid to the fixing roller, but in any case, the fixing or coating roller is coated with felt, cloth, etc. for liquid transmission and retention. It is common practice to supply anti-offset liquid by bringing the members into contact with each other. If the above-mentioned liquid transmission and holding member is left in contact with the roller when the fixing operation is stopped, the offset prevention liquid will drip onto the contact area, and this will occur when the fixing operation is restarted. If the toner image supporting material is soiled or the roller is made of a material that can be soaked in anti-offset liquid, the contact portion ((
In this case, the roller swells, deteriorating the quality of the fixed image, and causing other inconveniences such as wrinkles in the toner image supporting material. Therefore, when the fixing operation is stopped, the liquid is transferred and the holding member is moved away from the roller, but in such a case, a driving mechanism and a control means are required, making the configuration complicated, and thus is not preferable.

On the other hand, there is also a known method in which a silicone rubber roller whose rubber structure is impregnated with silicone oil is rotated in contact with the fixing roller to supply silicone oil (offset prevention liquid) to the fixing roller, but this method has the disadvantages mentioned above. Although it cannot solve the problem, it cannot be used in cases where the supply amount is too small and relatively fast fixing processing is required.

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to provide a device with a simple structure that solves the various disadvantages mentioned above. The fixing device of the present invention includes first and second rollers that pinch and convey a toner image supporting member to perform one image fixing process, and the first roller is coated with an anti-offset liquid. In the device, an anti-offset liquid is passed from the front side to the back side, and the control layer is made of a porous elastic material that has the property of increasing the permeability of the liquid when stretched. 1 roller,
Or, when the first roller or the rotating body rotates by sliding it on a rotating body for supplying anti-offset liquid to this roller, it stretches in the direction of rotation due to frictional force, and when this rotation stops, this stretching occurs. The deformation is restored, and this control layer is valved to supply offset prevention liquid from the liquid holding section to the first roller. The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a fixing device for a Shigeko photographic device to which the present invention can be applied. (2) is made by applying an offset-preventing resin coating 3 such as tetrafluoroethylene resin 11fi to the core metal pipe 2 using a constant roller. A heater 4 is disposed within the roller 1, and the circumferential surface thereof is heated to a temperature that melts the toner. The roller 5 is a pressure roller that presses the toner image supporting paper P between the roller 1 and the roller 1, and is made of a core metal roll 6 coated with a heat-resistant elastic layer 7 such as silicone rubber. The rollers 1 and 5 rotate in the direction of the arrow, gripping and conveying the paper P, and at the same time forming a toner image T.
is thermally fixed on the paper P.

Note that the image supporting surface of the paper P is pressed against the roller 1.

Reference numeral 8 denotes a silicone oil applicator described below, which applies the same oil to the circumferential surface of the fixing roller 1 to prevent toner offset and paper P from wrapping around the roller 1.

In FIG. 2, the applicator 8 has an oil storage tank 9 whose side and bottom walls are made of an elastic sponge such as RTV silicone rubber. A control layer 10 is attached to the bottom and side surfaces of the tank on the upstream side with respect to the rotational direction of the inner roller 1.

The upper part of this integrated structure is held by a rigid holder 11. This control layer IO can pass silicone oil from its front surface to its back surface.
It is a porous elastic material whose permeability increases when it is stretched, and is made of R'l silicone rubber or the like.

The control layer 10 is brought into surface contact with the circumferential surface of the fixing roller 1, and is so constructed that its thickness at the contact portion gradually decreases in the direction of rotation of the roller.

Now, silicone oil is put into the oil storage tank 9. Is this oil 4 Tsuba 9 Ml? It is absorbed and held by one comb sponge, and then passes through the micro holes in the wedged portion of the wrapping width layer 10 and is supplied to the roller l. The oil permeability of this sponge wall is better than that of the layer IO. Here, when the roller 1 rotates, the control layer 10 which is in surface sliding contact with the roller 1 is extended by Δ in the roller rotation direction as shown in the figure due to the frictional force between the control layer 10 and the roller 1. When the roller l stops rotating, the frictional force becomes O, the elastic deformation of itself disappears, and jψjlO returns to its original shape. Incidentally, since the bottom of the tank 9 is also bonded to the control layer 10, it physically elastically deforms with the layer 10.
Oil is supplied to the entire surface of II'111O in any deformed state, whether it is extended or contracted. In any case, as mentioned above, when the 1110 is stretched, it becomes easier for oil to pass through. Therefore, during constant Af operation, that is, when the roller 1 is rotating, the layer 10 extended by Δ as described above supplies and coats the roller 1 with an appropriate amount of oil at the top, but when the fixing operation is completed, the rotation of the roller 21 stops. When stopped, the layer IO returns to its original shape and reduces the ability of oil to pass through it, reducing it to 0. Therefore, even if the fixing down time is extended for a long time, excess oil will adhere to the fixing roller.
Therefore, when the fixing is restarted, the excess oil will not stain the paper. And also in FIG. 2, the control In 10 extends better in the thinner part of its wedge shape, i.e. in the front with respect to the direction of rotation of the roller 1, than in the rear. In other words, although the amount of oil that oozes out is small in the thicker parts of the wedge-shaped method, the rubber layer is more strongly rubbed against the roller in these areas, so the oil that oozes out is absorbed by the fine irregularities on the surface of the roller l (the semi-mirror surface of the tetrafluoroethylene resin). Even when finished, it is thoroughly rubbed within the roughness of 0.5 to several microns),
On the other hand, the thin part of the smoking shape provides an extremely thin and uniform coating of oil. In this way, there is no waste in the use of offset and paper on the roller 2, and the inconvenience that a large amount of oil accumulates on the roller surface can be prevented even when the apparatus is not in operation.

Further, in FIG. 2, the thickness of the layer 1o is continuously reduced in the direction of rotation of the roller 2, but the thickness may be reduced stepwise as shown at 10' in FIG. Furthermore, it is preferable to make a notch as shown in the figure on the inside of the sponge wall at the bottom of the liquid tank 9, that is, the bottom to which the control layer 10, 10' is attached. This increases the amount of oil that permeates into the sponge wall, and this wall also controls control 11? ! 10°10
', it becomes easier to stretch in the rotational direction of the roller 1.

In any case, in the apparatus shown in FIG. 2.3, the hardness of the control layer 10.10 is preferably 10 to 60 degrees, and the thickness at its thinnest point is preferably 20 to 500 microns. Further, the sponge constituting the tank 9 preferably has a hardness of 15 to 60 degrees, and the material is preferably the same as that of the control layer.

FIG. 4 is an explanatory diagram of another embodiment. In the illustrated example, the control layer 13 has approximately the same thickness in the direction of rotation of the roller 1, but a notch 14 is provided on the side of the layer 13 that contacts the roller 1. The interval between the notches 14 is determined by the distance between the notches 14 of the roller 1
Regarding the direction of one rotation, the rear part is also denser than the front part.

Therefore, when the roller I rotates, the layer 13 stretches better in the front part than in the rear part.

In FIG. 5, the spacing of the cuts 14 in the layer 13 is the same in the direction of rotation of the roller 1, but the depth of the cuts 14' increases towards the front in said direction. . Therefore, when the roller 21 rotates, Jmia stretches better at the front with respect to the direction of rotation of the roller I than at the rear.

Of course, by combining FIGS. 4 and 5, the cuts made in the control layer 13 may be made deeper toward the front in the direction of rotation of the roller l, and the intervals therebetween may be made narrower.

In any case, an appropriate amount of silicone oil is supplied to the surface of the row 21 due to the elongation of the control layer 13 during the rotation of the roller, and the rear part f of the layer 13 in the rotation direction of the row removal 21 is supplied.
ll! Apply oil to the fine irregularities on the surface of Row 21 on the l (low amount of elongation), and on the curved side where there is a large amount of elongation.
- Forming a thin oil film on the layer is similar to the example in Fig. 2.3.The thickness of the control layer 13 is 2
The thickness is preferably about 0 to 30110μ. The hardness of the layer 13 is 10 to 60 degrees, and the hardness of the H material in the tank 9 is 15 to 60 degrees.
degree is preferred. If the layer 13 is made of RTV silicone rubber, it is preferable that the tank 9 is also made of the same material (rl'V silicone rubber) from the viewpoint of fitting and integral deformation of the two.

In the second to fifth rows of figures, the f''i applicator 8 is used to attach the control layer 1 (1, 10', 13, 13') to the bottom of the approximately rectangular box-shaped tank 9 and to support it with the holder 11. Therefore, manufacturing is easy and the cost is low, and if the tank 9 is filled with oil, it can be used for a long period of time.Also, in the examples in Figs. 2 to 5, silicone rubber, urethane rubber, nitrile rubber'
4 +N Heat and oil resistant rubber control MI layer 10.10
', 13.13' should preferably be provided with a large number of minute continuous holes that penetrate from the front surface to the back surface, that is, from the surface that is brought into close contact with the oil retaining member 9 to the surface that is brought into sliding contact with the surface of the roller l. At this time, the diameter of the through hole increases as the control layer extends in the direction of rotation of the roller. It is most preferable that the through hole is completely closed by the elasticity of the rubber when the roller is not rotating, that is, when the control layer is not elastically deformed, and does not allow oil to pass therethrough. In this example, a film made of tetrafluoroethylene resin instead of rubber was used as the control layer 15. This tetrafluoroethylene resin film 15 has M fine continuous pores that penetrate from the front surface to the back surface, and the average diameter of the pores is 0 when not elastically deformed.
．． Preferably, the film thickness is 1 to 5μ, and the film thickness is 50 to 2000μ.

Membranes such as R-like are commercially available as Fluorobor (trade name, manufactured by Sumitomo Electric Industries, Ltd.). In FIG. 6, this membrane 15 is formed like a trough-shaped bag, and a comb sponge 9 impregnated with silicone oil is contained therein.

Are these supported by holder 11? However, the holder 11 supports the bag 15 at a high point H from the roller L on the front side with respect to the rotation direction of the roller 1, but supports the bag 15 at a place H below the roller L on the rear side with respect to the above direction. and supports the bag 15.

Therefore, when the row 21 rotates, the portion of the membrane 150 in sliding contact with the row 21 expands by ΔL as shown in the figure due to the frictional force between it and the roller 1. At this time, the sponge oil holding body 9' is also elastically deformed, so that the state in which the holding body 9 is in close contact with the inner surface of the bag 15 is maintained. In any case, as the membrane 15 expands, the diameter of the continuous fine pores described above increases, and an appropriate amount of oil passes through the pores and is applied to the roller I.

When the rotation of the roller 1 stops, the rubber sponge 9 returns to its original shape due to its elastic force, and the above-mentioned elastic deformation of the membrane 15 is also eliminated, returning to its original bag shape. This reduces the pore size of the membrane 15 and impairs oil passage. As shown in Figure 6, devices using a tetrafluoroethylene resin film with fine continuous pores as a control layer have excellent abrasion resistance and relatively good oil flow, making them suitable for devices that perform high-speed fixing processing. It has advantages such as being optimal, but on the other hand,
When low viscosity silicone oil suitable for the devices shown in Figures 2 to 5 is used, more silicone oil is observed to adhere between the roller 1 and the membrane 15 when the device is at rest than in the devices shown in Figures 2 to 5. It will be done. The rotation of the roller 1 stops and the film 1
This is because even if the elastic deformation of the membrane 15 is eliminated, the continuous pores of the membrane 15 do not close, but remain open, although they have a small diameter. Therefore, in a device like the one shown in Figure 6, room temperature (
It is preferable to use a high viscosity silicone oil having a standard viscosity +i of 1 ooocs or more at 25°C.

Such high viscosity oil is difficult to pass through the fine pores of the membrane 15 which is not elastically deformed, and an appropriate amount passes through the pores which are elastically deformed and the membrane 15 is stretched and enlarged in diameter as described above.

It should be noted that tetrafluoroethylene resin membranes having fine continuous pores, such as the aforementioned fluoropores, are more likely to be plastically deformed in the direction of stretching during the stretching process during membrane manufacturing than in the direction perpendicular to the stretching process, so as shown in Figure 6. In this case, a direction crossing this stretching direction,
Preferably, the roller 1 is brought into contact with the roller 1 in such a manner that the direction of rotation of the roller 1 coincides with the orthogonal direction.

In the above embodiments, the present invention was applied to the fixing roller l coated with a thin anti-offset color, but the fixing roller l covered with a thick silicone rubber layer was coated with silicone oil. Well, the pressure roller l
The oil may be applied using the applicator 8.

Further, as shown in FIG. 7, in a foot application device having an applicator roller 16 that is in contact with the fixing roller 1 and rotates by frictional force when the roller 1 rotates or by receiving driving force from a motor, The silicone oil may be applied to the roller 16 using the applicator 8 described above.

The oil applied to roller 16 is then applied to fixing roller l.

As described above, according to the present invention, even if the applicator is kept in contact with the roller, a large amount of anti-offset liquid will not adhere to the roller at the hour of the roller rotating body, and on the other hand, once the roller rotation starts for the first time, it will not continue. Star offset prevention liquid begins to be supplied. Therefore, there is no need for a complicated mechanism for bringing the applicator into and out of contact with the roller, and it has several advantages, such as reducing liquid consumption and preventing staining of the equipment and paper due to excess liquid.

[Brief explanation of drawings]

FIG. 1 shows an example of a fixing device 11 to which the present invention can be applied;
6 to 6 are diagrams for explaining essential parts of an embodiment of the present invention, and FIG. 7 is a diagram for explaining another example of a fixing device to which the present invention can be applied. 1 is a fixing roller, 5 is a pressure roller, 0 is a liquid tank and liquid absorption holder, 9 is a liquid absorption holder, 10, 10° 13, 13',
l5 is the control layer. Engraving of drawings (no change in content) No./Kasumi procedural amendment (method) January 1982? Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office, 1981 Patent Application No. 155602 2
Invention name fixing device 3 Relationship with the case of the person making the amendment Patent applicant Address 3-30-2 F-maru J', 111-ku, Tokyo Address m146 Do-maru, Ota-ku, Tokyo (-3-30-2 Canon Stock) Within the company (
(Telephone: 758-2111) 5. Date of amendment order: November 29, 1980 (shipping date) 6. Specification and drawings subject to amendment 7. Contents of amendment (1) Copy the entire text of the specification in attached sheet 9 ( (No content changes). (2) Engrave all the drawings as shown in the attached sheet (no changes will be made to the contents).

Claims (1)

[Scope of Claims] A first method for fixing an image by nipping and conveying a toner image support material.
In a fixing device that includes a second roller and a second roller and coats an anti-offset liquid on the first roller, passing the anti-offset liquid from the front side to the back side and stretching it at the time increases the permeability of the liquid. The control layer is made of a porous elastic material having the property of Alternatively, when the rotating body rotates, it is stretched in the direction of rotation due to frictional force, and when this rotation stops, this stretching deformation is restored, and the anti-offset liquid is first supplied from the liquid holding part through this control layer. A fixing device characterized in that the fixing device is configured to feed the roller to the roller.