DE2344810A1 - TONER IMAGE FUSER - Google Patents

Description

PATENTANWÄLTE HENKEL— KERN - FEILER - HÄNZEL— MÜLLER

DR. PHIL. DIPL.-ING. DR. RER. NAT. DIPL.-ING. DIPL.-ING.

TELEPHONE: (08 II) 66 3197. ίΓ3 ^ 91-92 BDUARD-S CH M ID- STRASSE 2 BAVARIAN MORTGAGE AND

TELEGRAMS: ELLIPSOID MÜNCHEN D- 8 00 0 MÜN CH FN 90 WECHSELBANK. MUNICH NO. 318-85 IH

POSTAL CHECK: MCHN 162147-809

Konishiroku Photo Industry Co., Ltd. Tokyo, Japan

- 5th SEP. 1973

Toner image fixing device

The present invention relates to a toner image peeling device for electrostatic recording, the electrostatic Printing or electrophotography, and particularly relates to thermal fusing apparatus of toner images which has a thermal fixing device which is associated with a toner image on a carrier is contactable.

A toner image formed by an electrostatic process has extremely poor adhesion to the carrier and can therefore easily be damaged by mechanical action, so that it is necessary to obtain a permanent image on the carrier must be fixed.

In general, thermal fixing devices are used for fixing the toner image, which are divided into two Let divide types, one of which uses a heat radiation and the other uses a heated fixing member having that with that bearing the toner images

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Carrier can be brought into contact »In the first-mentioned type of device, the toner images are generated by thermal radiation heated and fused so that they adhere to the carrier without contacting the toner images with the heat source. This device has the advantage that the toner images do not come into contact with any parts during fixing and therefore cannot be mechanically damaged either, but on the other hand this device has the disadvantage subject to that the fixing speed because of the poor thermal conductivity of the toner image itself is low and, in addition, a large amount of thermal energy is required.

Although the second type of apparatus in which the toner image is formed with the thermosetting member, e.g. heated roller, comes into contact with the shortcomings of the aforementioned device using thermal radiation do not adhere, the toner image or part of it can melt and stick to the thermosetting member, whereupon the toner adhering to the fixing member is transferred to the image carrier again, so that fog is formed or blurring, which in the following is referred to as "transfer printing phenomenon" are designated.

To eliminate these shortcomings, it has already been proposed that the surface of the thermosetting member with a to cover material such as polytetrafluoroethylene, hereinafter referred to as "transfer printing preventing material", to thereby prevent the fused toner from adhering to the heat-setting member, further a release agent, such as silicone oil, and then the portion that comes into contact with the toner image on a fusing the toner to a sufficient temperature.

This fixing device in which the thermosetting member and the toner image are brought into contact with each other are capable of the aforementioned deficiency of the known

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To switch off devices largely. However, the use of such a thermosetting member alone is sufficient does not do enough to completely eliminate the transferring phenomenon and also the transferring preventing material proves to be poorly heat-resistant, especially if it is in permanent use for a long time, so that for Only special synthetic resin materials with a comparatively low melting point can be used for the toner. As a result the poor thermal conductivity of the material preventing transfer printing is also a very significant one Amount of heat energy required, making temperature control difficult. Because of poor durability of the transfer preventive material as well as the difficulty of obtaining surface uniformity In addition, in the manufacture of the device, irregularities in the contact with the Toner image caused.

The invention is therefore based on the object of creating an improved toner image fixing device, which the aforementioned defects no longer adhere and which a thermosetting member that can be brought into contact with the image carrier having.

This task is performed with a toner image fixing device according to the invention achieved in that the heat-setting device which can be contacted with the toner images held on a carrier is provided with a microporous metallic surface, which is attached to a to fix the Toner images on the carrier can be heated to a sufficient temperature, and a release agent applicator for applying having a release agent on the surface.

The microporous metal surface of the thermosetting device can be made of a metal or a metal oxide, e.g.

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made of alunite or alumite or aluminum oxide, and is provided with a large number of fine pores with a size of less than Ip- with a porosity (percentage of the proportion of the total area occupied by the pores) of about $ 25, preferably 10-2.0% . '

The thermosetting device according to the invention can be produced, for example, in such a way that the Surface of a roller or roller, preferably a metal roller, polished and the polished surface with a Anode-oxidized film made of aluminum (alumite treatment) coated or a metallic film by metal spraying is formed.

This process is very easy to carry out, and if a roller with a polished surface is used as the starting workpiece is used, no polishing is required after treatment, so that the desired product is obtained can easily be produced with a uniform coating thickness. The other hand is in connection with the well-known Thermofixing devices point out that in the treatment with a transfer printing preventing material final polishing of the surface of this material layer is indispensable, it being due to the properties this material is also difficult to achieve a uniform finish polishing.

In addition, in the device according to the invention, the section of the thermosetting device which can be contacted with the toner is used heated to a temperature so high that the toner begins to melt and adhere to the carrier will. Although this temperature depends on the type of toner material used and the type of toner image on the support can vary within a certain range, it is in the case of a paper support

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usually in the range of about 150-230 ° C and preferably from about 160 - 190 ° C.

The section of the heat-setting device that comes into contact with the toner is coated with a release agent, such as silicone oil, and also heated to the temperature indicated above, in order to then with the on the Carrier formed toner images to be contacted, with an excellent fixation achieved and equal « A transfer printing or blurring can be prevented in good time. This effect is attributed to the fact that the release agent penetrates into the fine pores and is retained in them.

Since this thermosetting device also has a metallic surface, it has good thermal conductivity as well as excellent durability and heat resistance.

In the following, preferred embodiments of the invention are explained in more detail with reference to the accompanying drawings, however, it should be pointed out that further modifications are possible within the scope of the invention are. Show it:

Fig. 1 is a schematic representation of an embodiment of the invention and

2 shows a schematic representation of a modified one Embodiment of the invention

In Fig. 1 at 1 an image carrier, e.g. a sheet of paper, shown which carries the toner images 2 and which is advanced to the toner images 2 with a thermosetting device 3 to bring into contact.

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Guide members 5 and 5 ¹ support the promotion or discharge of the image carrier 1 through or from the device. The guide member 5 is arranged such that a passage gap for the carrier 1 and the toner images 2 carried by it is formed between the thermosetting member 3> and a roller 6 which is arranged so that it presses against the fixing member 3>.

The thermosetting device 2 consists of a hollow metal roller 4 with a metal layer J ₃ which has a microporous metal surface. The fixing device preferably consists of an aluminum roller 4 and an alumite layer 7.

A heater 8 is arranged inside the roller 4, and the surface of the metal layer 7 becomes coated with a release agent 12, such as silicone oil, which is supplied from a release agent application device 11 will.

The release agent application device 11 consists of a roller 13 immersed in the release agent 12, a release agent-permeable material 9 in contact with the roller, and a support member 10 for this material 9.

The release agent is through the rotating roller and the material 9 evenly on the surface of the Metal layer 7 applied. The roller 6 preferably has a fixing effect, sufficient elasticity and non-adsorbability for the release agent and excellent in durability and resistance to Warmth. This roller 6 must be able to be pressed against the thermosetting device at least during the fixing process;

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for this reason, this roller is preferably made of an elastic material such as silicone rubber, or is on its surface is coated with a flexible material such as polytetrafluoroethylene.

In the operation of the above toner image fixing device, the carrier carrying the toner images is between the Thermosetting device j5 and the roller 6 inserted, the toner images with the surface of the metal layer 7 of the thermosetting device 5, which was heated by the heating device 8 and that of the Applicator 11 carries supplied release agent. When the thermosetting device rotates. J5 and the Roller 6, the toner images are evenly melted and fixed on the carrier.

If for the roller 4 of the thermosetting device J5 an aluminum roller and an alumite ^ as the metal layer 7 Layer are used, excellent thermal conductivity can be achieved.

The thickness of the alumite layer can also be easily controlled in accordance with the manufacturing conditions. In the illustrated embodiment of the "invention, good results can be achieved if the thickness of this layer is approximately 10-50 yes ."

Fig. 2 is a schematic representation of a fixing device according to a modified embodiment the invention. In this case, a carrier 21 carrying the toner images 22 lies on a belt 24 which is wound around a roller 25 and another, not shown, the roller 25 opposite roller is passed around. The band 24 arrives the position of the elastic roller 25 in pressure contact

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with the thermosetting device 23> the carrier 21 being conveyed to that position by the belt.

The thermosetting device 23 consists of a hollow roller 26 and one made by a metal spraying process metallic layer 27 * formed on it, the surface thereof is provided with a large number of small pores. A heating device 28 is provided in the interior of the roller 26. The surface of the metallic layer 27 on the thermosetting device 23 is at a suitable location with a material 30 permeable to release agents the lateral surface of a roller 29 contacted. The one with the Material 30 coated roll 29 forms together with another roll 31 which is immersed in the release agent Release agent application device. When the roller 31 is rotating, the separating agent is thus in contact with it standing material 30 supplied, the release agent is further transferred to the surface of the anetallic layer 27 as the roller 29 rotates.

In this fixing device, the image carrier 21 is when the roller 26 rotates in the gap between the Thermofixing device 23 and the tape 24 introduced and thereby by the heating device on a corresponding Surface temperature heated, so that the toner images are melted and fixed to the carrier 21.

1 and 2 illustrate only certain embodiments of the invention, which also in others Embodiments can be realized. For example, the release agent applicator does not necessarily need to be arranged in such a way that it continuously feeds the release agent; can only be supplied when it is needed.

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This is made possible by the fact that the thermosetting device according to the invention has an excellent release agent holding capacity, so that, more precisely, the arrangement can be made such that the rollers 13> or 29 or yi are only set in rotation when a release agent is required , ie the thermosetting device only needs to be contacted with the material 9 or 29 when this is necessary.

In addition, the release agent applicator can also be provided with a belt and rollers to support the belt are formed. In this case, for example, a tape made of a material permeable to the release agent can be used Run around roller 29 according to FIG. Furthermore, the arrangement can also be chosen so that the thermosetting device and the roller 6 or the belt 24 synchronously with the interposition of the carrier carrying the toner images are pressed against each other. By such an arrangement, the service life of the roller β or des Bands 24 to be improved.

In addition, when the roller 4 in the embodiment According to Fig. 1 consists of a microporous metal roller, it is possible in some cases, the release agent of the Feed inside. In addition, the thermosetting device cannot be heated from the inside, but rather done by contact with a heated roller.

In the above-described toner image fixing device of the present invention, the toner images are not transferred to the thermosetting device, the fixing device also having excellent durability and has heat resistance, so that it can be fixed uniformly and reliably and the service life of the device is greatly improved.

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In addition, the device according to the invention has all the advantages of the known thermosetting devices, so that it offers an extremely high practical value.

If only a simple metal roller is used as the heat-setting device, it is impossible to use the To prevent transfer printing or smearing of the toner images. In addition, the fixation takes place in this case unevenly, which affects the image properties will.

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Claims (4)

. 234: 481 - 11 claims Toner image fixing device, characterized in that the heat fixing device (J >> 2J5) which can be contacted with the toner images (2, 22) held on a carrier (1, 21) is provided with a microporous metallic surface (7 > 27) which is attached to a a temperature sufficient to fix the toner images on the carrier can be heated, and has a release agent application device for applying a release agent to the surface. 2. Apparatus according to claim 1, characterized in that means for contacting the toner image with the. Thermosetting device is arranged opposite the latter. J). Device according to Claim 1, characterized in that the separating agent application device has a material which is permeable to the separating agent. 4. Apparatus according to claim 1, characterized in that the release agent application device has a rotating roller which touches the thermosetting device '' and to which a release agent is applied. ^ 0981 1/1112 Blank page