JPS6362743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus that transfers and simultaneously fixes a toner image formed on a sheet-like electrophotographic photoreceptor onto a transfer sheet such as plain paper.

With electrophotographic copying machines that transfer the final image onto plain paper, etc., the resulting final image has excellent fade resistance, but the drawback is that the copying equipment is large and expensive. have. For this reason, there was a demand for a new and inexpensive technology instead of the technology that has been used in the past. For example, regarding the transfer and fixing system, instead of the conventional corotron transfer and hot roll fixing devices, a different transfer and fixing system that is compatible with lower costs was required.

Therefore, the inventors of the present invention have worked diligently to develop methods for transferring and fixing created toner images, and have now provided a transfer/fixing device that is small and can be manufactured at low cost and that can perform transfer and fixing at the same time. It is something.

As a device that performs simultaneous transfer and fixing, a transfer and fixing device as shown in FIG. 1 is conventionally known.

This is an infrared light source in a conveyance system consisting of a roll body 1, small roll bodies 2 and 3 that rotate following the roll body, and a small roll body 4 that rotates while being engaged with these rolls by a transparent endless belt 5. It is a combination of 6. This infrared light source 6 emits near-infrared light with a dominant wavelength of 1.2 μm, and is configured to be directed toward the rotation axis of the roll body 1 by a reflecting mirror 7 provided later. To explain the operation when using this device, the transparent sheet-like photosensitive material 10
When the toner image formed on the transparent sheet-like material 100 is overlapped with the transfer sheet 101 and inserted from the entrance A, the toner image on the transparent sheet-like sensitive material 100 absorbs infrared rays when it reaches directly under the infrared light source 6. The toner image eventually begins to melt, and the toner image is transferred and fixed before passing through the small roll body 2. After completion of transfer and fixing, transparent sheet-like photosensitive material 100 and transfer sheet 10
1 is discharged from the discharge port B, and by peeling off both sides, a normal toner image that is a mirror image of the toner image on the transparent sheet-like sensitive material is transferred to the transfer sheet 1.
01.

However, in this type of transfer fixing method, the melting temperature of the toner and the transparent entresive belt 5
If there is not much difference in temperature from the thermal softening temperature of the transparent sheet-like sensitive material 100, there is a drawback that the endless belt 5 and the transparent sheet are deformed before the toner melts or melts. To prevent this, there are restrictions on the selection of materials for the toner, endless belt, and transparent sheet.
For example, it may be necessary to select a toner whose melting temperature is about 20°C lower than the softening temperature of the endless belt and the transparent sheet, and in addition to the melting and softening temperatures of each material, the transparent endless belt 5 The infrared transmittance is very important, and if this infrared transmittance is low, the transparent endless belt 5 will be deformed due to heat, and the toner will not melt. For example, if a 25μ thick polyethylene terephthalate film known as Mylar manufactured by EI Dupont is used as a transparent endless belt, this film will transmit 55% to 29% of infrared light of 0.6 to 2.5μ. The dominant wavelength is 1.2μ.
Only about 50% of the light from an infrared light source is transmitted. Especially in this process, it is necessary to apply light pressure, so the transparent endless belt 5
It is necessary to press the transparent sheet-like photosensitive material 100 with the following steps. Also as a support for the transparent sheet-like sensitive material 100,
If Mylar is used, the infrared rays will have to pass through these two transparent bodies, and the amount of infrared rays that will pass through will be even smaller. For this reason,
Toner may not melt and cause transfer defects.

Also, when using 10μ thick polypropylene as a transparent endless belt, this film
It has a transmittance of more than 90% for infrared light of 0.3 to 2.5μ, which seems to be very advantageous in melting toner, but the heat distortion temperature is as low as 110℃, and it cannot be used on transparent endless belts. When toner adheres to the surface, this area absorbs heat and becomes hotter than 110 degrees Celsius, resulting in holes, and infrared rays are blocked by toner stains, resulting in poor transfer. .

As described above, the conventional apparatus has problems in softening point and infrared transmittance due to the use of a transparent endless belt, and is extremely susceptible to dirt.

The present invention was invented in view of the problems of the prior art described above, and is capable of simultaneously performing transfer and fixing without using a transparent endless belt, which is the main cause of the problems.

That is, the present invention provides an apparatus for simultaneously transferring and fixing a toner image formed on a transparent sheet-like electrophotographic light-sensitive material and a transfer sheet to be copied, which includes: a cylindrical roll that transmits almost infrared light; a radiation source consisting of an infrared light source and a reflecting mirror provided inside the cylindrical roll; a transparent guide roll that rotates to follow the outer periphery of the cylindrical roll and a discharge roll that also serves as a cleaning; and the cylindrical roll. The present invention provides an electrophotographic transfer and fixing device comprising a press plate configured to extend along the outer periphery of the press plate and having fine fibers arranged on its surface.

FIG. 2 shows a transfer fixing device of the present invention.

This transfer fixing device, an infrared light source 11 and a reflecting mirror 12
a cylindrical roll 20 which uses as a radiation source and transmits most of the near-infrared light, a guide roll 15 that rotates following the cylindrical roll 20 and feeds a pair of a transfer sheet 101 and a transparent sheet-like sensitive material 100, and a discharge roll 16 that sends out a pair. , transfer sheet 101 to transparent sheet-like sensitive material 100
It consists of a pressing plate 13 having fine fibers 14 for pressure contact. The surface of the discharge roll 16 is covered with felt, and has the function of discharging copies and cleaning the surface of the cylindrical roll. Transmitting most of the near-infrared light means transmitting at least 70% or more of the near-infrared light.

The cylindrical roll 20 is made of a material that is resistant to infrared rays and has high infrared transmittance, and usually transparent heat-resistant glass such as Pyrex glass is used. The radius of the cylindrical roll is appropriately determined depending on the toner used, the infrared light source, and the like.

Both natural fibers and synthetic fibers can be used for the fine fibers provided on the pressing plate, but in terms of their resistance to infrared rays, animal fibers such as wool, fluorine-based resins such as polyfluorinated ethylene (known by the trade name Teflon), and polyamide are recommended. etc. can be suitably used, and inorganic fibers such as glass fibers can also be used. These fibers can be in the form of non-woven fabrics, felts, flocked molded products or raised molded products, but generally wool felt pasted on a pressing plate is used. As a result of providing this pressure plate, the toner on the transparent sheet-like sensitive material is effectively transferred to the transfer sheet without heat loss. It is necessary that the pressing plate covered with fibers sufficiently feed, unwind, and transport the photosensitive material and transfer sheet, and for this purpose, the pressing action of the pressing plate is sufficiently transmitted to the transport roll, the photosensitive material, and the transfer sheet. A fiber material is selected which has properties and structure that allow it to be used, and which also has thermal insulation properties. As the transfer sheet 101 fed by the cylindrical roll 20 and the guide roll 15, commercially available paper, synthetic paper such as styrene foam, polymer film made of vinyl acetate polymer, etc. can be used, and it can be used as a transparent sheet-like sensitive material. has a structure in which an electrophotographic light-sensitive material layer is formed on a support 99 that is transparent to visible light and infrared light, and a toner image is formed on this layer. Transparent sheet-like sensitive materials include, for example, polyethylene terephthalate (manufactured by EI DuPont,
An electrophotographic photosensitive material layer consisting of a photoconductive material such as polyvinyl carbazole, TiO ₂ or ZnO, a polymer binder such as polycarbonate, polyacrylic acid ester or polyester resin, and others is formed on a support made of a material (trade name "Mylar"). In electrophotography, sensitive materials used for contact reflection exposure are usually used.

To explain the operation according to the figure, a support film 99 that is transparent to visible and infrared rays is provided.
A toner image 97 formed on a transparent sheet-like sensitive material 100 having an electrophotographic photosensitive material layer 98 is overlapped with a transfer sheet 101 and inserted into an entrance 18 of a transfer fixing device as shown in the figure. The cylindrical roll 20 is
Since they are rotating in the direction of arrow A, the sheet-like sensitive material 100 and the transfer sheet 101 are sent by the guide roll 15 to a heating area where infrared rays are radiated. This heating area is focused by the reflecting mirror 12 on the cylindrical roll and between the contact points of the cylindrical roll and the guide roll 15 and discharge roll 16, respectively, and the toner absorbs infrared rays due to the pressure of the fine fibers 14. is melted and the transfer sheet 101
flows into. The photosensitive material with the toner dissolved therein and the transfer sheet pass through a discharge/cleaning roll 16 and come out to a discharge port 17. When the transparent sheet-like photosensitive material 100 is released, the transfer sheet 101 is separated from the transfer sheet 101 to obtain a transfer sheet 101 having an image to which the toner image has been transferred and fixed. Here, even if dirt such as toner adheres to the heat-resistant glass of the cylindrical roll, the glass surface is constantly cleaned by the discharge roller/cleaning roller 16, so that no local transfer failure occurs.

As described above, the transfer fixing device of the present invention uses a cylindrical roll that is sufficiently transparent to infrared light instead of a transparent endless belt, and transfers and fixes while being pressed by a pressure plate, resulting in transfer failure due to heat loss. There are no problems such as holes forming due to dirt such as toner, and since the ejection roll also serves as a cleaner, the glass surface is cleaned and there is no need to worry about localized transfer defects.

(Example) Polyethylene terephthalate film (E.
A transparent support film (trade name "Mylar" manufactured by I-Dupont) was coated with an organic photosensitive material consisting of polyvinylcarbazole, maleic acid, and Victoria Blue as a dye, to prepare an electrophotographic material. A toner image was produced on this electrophotographic material using a conventional electrophotographic system. Plain paper was folded over the toner image side and inserted into the apparatus of the present invention (see Figure 2) with the commercially available paper facing down. The toner had a low melting temperature of 85°, and the device was rotated in the direction of the arrow at a linear velocity of 40 mm/sec. When the photosensitive material-plain paper pair that came out from the discharge port 17 was peeled off, a toner image that was normal to the original was obtained on commercially available paper.

[Brief explanation of drawings]

FIG. 1 shows an outline of a conventional transfer fixing device, and FIG. 2 shows a transfer fixing device of the present invention. 1... Roll body, 2, 3, 4... Small roll body, 5...
Endless belt, 6... Infrared light source, 20... Cylindrical roll body, 13... Press plate, 14... Fine fiber, 15
...Guide roll, 16...Discharge roll/cleaning roll, 17...Discharge port, 18...Carry-in port.

Claims (1)

[Scope of Claims] 1. In an apparatus that simultaneously transfers and fixes a toner image formed on a transparent sheet-like electrophotographic light-sensitive material and a transfer sheet to be copied by overlapping the same, a cylindrical shape that transmits almost infrared light. a radiation source consisting of an infrared light source and a reflecting mirror provided inside the cylindrical roll; a guide roll that follows and rotates around the outer periphery of the transparent cylindrical roll; a discharge roll that also serves as a cleaner; and the cylindrical roll. A thermal transfer fixing device for electrophotography, which is configured to run along the outer periphery of a roll and a press plate with fine fibers arranged on its surface.