JPH0261749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device for a movable sheet body configured to heat the movable sheet body while bringing the movable sheet body into contact with a heating body.

Conventionally, in recording devices such as electrostatic recording and electrophotography, an electrostatic charge image is formed on an image carrier such as a photoreceptor drum, and this is developed using a developer mixed with toner and carrier as necessary. and transfer the obtained toner image onto a transfer sheet, for example electrostatically,
Images are formed based on the process of further fixing.

However, when a toner image is electrostatically transferred onto a transfer sheet (recording material) using a transfer electrode such as a corona discharger, charge disturbance occurs and the resolution of the toner image is reduced. Furthermore, when a conductive magnetic toner, which has been recently recommended, is used as the toner, further charge disturbance occurs, resulting in a state in which transfer is virtually impossible.

As a method to improve the above-mentioned drawbacks of electrostatic transfer, attempts have been made to press transfer onto a transfer sheet using a pressure roll, but the transfer efficiency is poor and only about half the amount of toner image is transferred. have a disability.

Therefore, for example, in Japanese Patent Publication No. 46-41679, Japanese Patent Publication No. 48-22763, Japanese Unexamined Patent Publication No. 49-78559, and US Pat. A method has been proposed in which the above-mentioned toner image is pressure-transferred, and the transferred toner image is heated and melted using a heating roll, and then pressure-transferred and fixed (transfer-fixed) onto a transfer sheet. In such a method, a toner image is transferred by pressure onto the surface layer of a rubber-based transfer layer, such as silicone rubber or fluoro rubber, which has releasability on the one hand and has the property of adhering fine particles when pressed. The toner image on the transfer layer is heated and melted by contact with a heating body such as a heating roll, and is transferred under pressure onto a transfer sheet fed at the same time and fixed. In other words, the toner image melted by heating is easily transferred and fixed onto the transfer sheet based on the above-mentioned releasability of the transfer layer, so there is no reduction in the resolution of the toner image due to the transfer process, and moreover, the transfer rate is high. is expected to be realized.

In such a recording apparatus, it is desirable to pre-heat the transfer paper before transferring and fixing in order to improve transfer and fixing properties. For this purpose, a hot plate may be brought into contact with the transfer paper sent to the transfer fixing section. For example, this hot plate may be applied to the circumferential surface of the pressure roll that is pressed against the heating roll while sandwiching the transfer paper, or it may be arranged so that the transfer paper can be pressed in front of the pressure roll. .

However, in such preheating, the transfer paper is conveyed while being in contact with a pressure member that presses the transfer paper against the hot plate over a considerable area, so there is a large amount of friction between the two. It was found that the transfer paper was prone to paper jams.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that can effectively heat a moving sheet such as transfer paper without clogging.

According to the present invention, this purpose is to transfer a toner image on an image carrier (for example, a photoreceptor drum 11 to be described later) to an intermediate transfer body (for example, a belt 15 or a roll 2 to be described later).
5) in a recording device that transfers and fixes the image onto a moving sheet member (for example, transfer paper 14 described later),
A moving sheet of a recording device configured to heat the moving sheet while contacting the moving sheet along a heating body, and transfer and fix the toner image on the intermediate transfer member onto the heated moving sheet by conveying the moving sheet. In the heating device for a body, the heating body is a rotating pressure roll (for example, the pressure roll 19 described below) that has a heat source and has a peripheral surface made of silicone rubber, and the heating body is configured to heat the moving sheet body. A pressure contact member (for example, 4 described below) that presses against the body is provided, and the pressure contact member is a flexible heat-resistant band-like member (for example, heat-resistant tape 5 described below) having a smaller coefficient of friction than the circumferential surface of the heating element, and This is achieved by a heating device for a moving sheet body that is intermittently stretched in a direction perpendicular to the moving direction of the sheet body to form a pressure contact portion.

According to the heating device of the present invention, the pressure contact area of the movable sheet body with respect to the heating body is provided intermittently along the direction of movement of the movable sheet body and at the same time in a direction crossing the direction of movement, so that the sheet body is in contact with the pressure member. The materials are not brought into contact with each other more than necessary, and are transported smoothly while being sufficiently heated by the heating element.

Therefore, the sheet body is heated to a desired temperature without clogging, and is smoothly sent to a predetermined location (for example, the transfer/fixing section as described above).

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings.

1 and 2 show an example of a heating device using a hot plate 1 according to a reference example of the present invention.

The hot plate 1 is heated by the heater 2 to a temperature sufficient to prepare the transfer paper 14. A pressing member 4 for pressing the transfer paper 14 against the upper flat surface 3 of the hot plate 1 is arranged as shown in the figure. That is, this pressure contact member 4 has a plurality of heat-resistant tapes 5 stretched in parallel along the moving direction 8 of the transfer paper 14, each of which has both ends fixed to a tape support plate 6, and each tape 5 is held by a tape presser 7. It is configured to be pressed onto the hot plate 1.

What should be noted here is that since each tape 5 is arranged in parallel, contact areas or pressure areas between the tape and the transfer paper 14 exist intermittently in a direction substantially perpendicular to the moving direction 8 of the transfer paper 14. This is what we are doing. This reduces the contact area between the tape 5 and the transfer paper 14, effectively preventing paper jams caused by friction between the two, and also allows the transfer paper 14 itself to move smoothly. can.

To convey the transfer paper 14, gaps between each tape 5,
In particular, a conveyance roller 9 is arranged in the gap at the center,
It is desirable to convey the transfer paper 14 while pressing it with this roller 9.

The heat-resistant tape 5 is preferably made of a flexible heat-resistant resin with a small coefficient of friction, such as fluorocarbon resin such as Teflon (registered trademark), polyimide such as Kapton (registered trademark), polyester, or fiber-containing resin. . Such a tape deforms to closely follow the surface shape of the hot plate 1 in the press-contact state shown in FIG.
can be made sufficient, and can be easily moved.

In order to heat the transfer paper more effectively, it is preferable to form the surface of the heat plate 1 on the transfer paper side into a convex curved surface as shown in FIG. In this case, since the hot plate 1 is formed into a curved surface, the tape 5 bites onto this curved surface, so that the transfer paper 14 is in sufficient pressure contact, and the heating is performed satisfactorily. Moreover, the tape presser 7 shown in FIG. 2 is not required.

FIG. 4 shows an embodiment of the present invention, in which a heating roll 19 having a curved surface similar to that of the heating plate 1 shown in FIG. 3 is used. This heat roll 19 is heated to a temperature sufficient for heating the transfer paper by a heat source 19A such as a built-in heater lamp, and can also be used as a pressure roll of the transfer and fixing section described later, making the recording device more compact and transferring paper. This is useful in terms of improving transportability, etc. In this example as well, the transfer paper 14 can be heated well as in FIG. 3, and at the same time the paper can be fed by the roll 19, so the above-mentioned conveyance roller 9 can be omitted.

In addition, in both the examples shown in FIGS. 3 and 4, the pressure contact member 4
This is made up of a plurality of heat-resistant tapes 5 fixed by a support plate 6 in the same way as shown in FIGS. 1 and 2.

Next, a preferred mode of use of the above pressure contact member 4 will be explained with reference to FIG.

The apparatus shown in FIG. 5 is a recording apparatus having an intermediate transfer belt 15, in which a known latent image forming mechanism 12, Developing mechanism 1
3 and a cleaning mechanism 14 are provided sequentially in the rotational direction. In the transfer area A between the developing mechanism 13 and the cleaning mechanism 14, an intermediate transfer body 15 made of an endless belt is pressed against the outer peripheral surface of the toner image holding body 11 by a pressure (transfer) roll 16. The intermediate transfer belt 15 is made of a flexible film substrate made of polyimide or the like having a thickness of 10 to 100 .mu.m and coated with an adhesive layer of silicone rubber having a thickness of 10 to 100 .mu.m, for example. The intermediate transfer belt 15 includes, in addition to the pressure roll 16,
The heating roll 1 is bridged between the heating roll 17 and the tension roller 18 and is moved at a constant speed in the same direction as the toner image carrier 11 in the transfer area A.
7 to the intermediate transfer body heating area B. Also,
A cleaning roller 22 is disposed opposite the tension roller 18, and a charge eliminating member 23 such as a charge eliminating brush for preventing the belt 15 from being charged is further provided.

The intermediate transfer belt 1 on the heating roll 17
Transfer fixing area C at or near the departure point of No. 5
In this case, a pressure roll 19 as a heat roll is provided so as to be pressed against the roll 17. In the transfer material moving path of the transfer material 14 made of recording paper, which is set to pass through this transfer and fixing region C, the third
The pressure member 4 shown in the figure is disposed in contact with the pressure roll 19.

Using the apparatus configured as described above, in this example, the toner image formed on the toner image carrier is finally transferred and fixed onto the transfer material in the following manner.

First, the toner image T on the toner image holding member 11 is formed by developing the latent image formed by the latent image forming mechanism 12 with the developing mechanism 13 . That is, when electrophotography is used, the toner image carrier 11 is composed of a selenium-based, organic compound-based, zinc oxide or cadmium sulfide-based binder type, or other electrophotographic photoreceptor, and has a latent image forming mechanism. 12, the entire outer peripheral surface of the toner image holding member 11 is electrically charged and then imagewise exposed to form an electrostatic latent image. In addition, when electrostatic recording is used, the toner image carrier 11 is constructed of a dielectric material consisting of a conductive base and a dielectric surface layer, and image signals are transferred to an electrostatic latent image using a multi-stylus electrode or an ion control electrode. A latent image is formed by converting the image into a latent image. Further, when a magnetic recording method is used, the toner image carrier 11 may be made of a magnetic material, and an image signal may be converted into a magnetic signal by a magnetization head to form a magnetic latent image.

If the latent image formed in this manner is an electrostatic latent image, the developing mechanism 13 makes the latent image visible using toner, which is colored charged particles charged to the opposite polarity to that forming the latent image. It is considered to be a statue. When the toner used here is a one-component conductive magnetic toner, development is achieved by the charge induced in the toner. When a one-component conductive magnetic toner is used and a magnetic brush development method is used, the toner layer is formed as a single particle layer or a thin layer close to it.
It is particularly preferred in that the final image obtained is excellent in image quality, durability, and high-speed developability, and good transfer is possible without selecting a transfer material. When the latent image is a magnetic latent image, it is sufficient to develop it with magnetic toner, and it is possible to prevent the occurrence of blurring of the image during transfer and to obtain a clear image.

Toner image carrier 1 formed as described above
1 is transferred onto the intermediate transfer belt 15 in the transfer area A by the pressing force of the pressing roller 16.

The adhesive layer, especially the silicone rubber layer, of the intermediate transfer belt 15 overcomes the toner retention force of the toner image carrier 11 in the transfer area A due to the moderate adhesiveness of the surface at low temperatures and the rubber elasticity that contains the toner. Toner can be sufficiently captured on the transfer body side. In addition, since the surface energy of the silicone rubber layer is sufficiently small compared to normal transfer material materials, the toner is heated from the surface of the transfer material side in the transfer fixing area C, which will be described later, and the toner becomes fluid. When the transfer material is brought into pressure contact with the toner, the toner strongly adheres to the transfer material and is almost completely transferred and fixed onto the transfer material.

The heating roll 17 has a heater 17A made of, for example, an infrared lamp built into a hollow metal roll made of aluminum or the like, and controls the temperature of the surface of the metal roll within an appropriate range. As a result, the intermediate transfer belt 15 and the toner image T thereon are heated in the area between the contact start point E with the intermediate transfer belt 15 and the transfer fixing area C, that is, the intermediate transfer body heating area B, and the toner image T on the intermediate transfer belt 15 is heated in the area C. The toner image has sufficient transfer and fixing properties. The pressure roll 19 in the transfer fixing area C is configured as an auxiliary heating roll that further improves transfer fixing properties, and is a heat-resistant elastic roll provided with a surface layer of silicone rubber or the like, and has a built-in heater lamp 19A (fourth roll). (see figure) may be used. Further, as described in FIG. 4, the transfer material pressing member 4 in the illustrated example has a shape adapted to contact along the outer peripheral surface of the pressing roll 19, and the transfer material is pressed against the roll 19.
As a result, the intermediate transfer body 15 in the transfer fixing area C
It is preferable to contact and heat the surface of the transfer material to the extent that the upper toner image is sufficiently transferred and fixed to the transfer material. Here, the friction coefficient of the surface of the press roll 19 is the same as that of the press member 4.
Therefore, as the surface moves due to the rotation of the pressure roll 19, the transfer material slides on the surface of the tape 5 and the roll 19 is made larger than that of the tape 5.
is heated and conveyed to the transfer fixing area C. The transfer material heated in this way is transferred to the transfer fixing area C.
, the intermediate transfer belt 15 and the pressure roll 1 are heated together with the toner image by the heat roll 17 in advance.
As a result, the toner of the toner image is pressed in a fluidized state due to heating, so that it is reliably transferred and fixed onto the transfer material.

The transfer material that has passed through the transfer fixing area C is normally conveyed along the intermediate transfer belt 15 and separated from the intermediate transfer belt 15 by a tension roller 18 . Here, if the diameter of the tension roller 18 is made small, it is possible to easily separate the transfer material from the intermediate transfer belt 15, but by making it swing further, it is possible to prevent the intermediate transfer belt 15 from shifting. You can also do that. The intermediate transfer belt 15 that has passed through the transfer and fixing area C is partially cooled naturally, undergoes transfer again in the transfer area A, and then repeats the transfer and fixing process in the transfer and fixing area C.

In the figure, 21 is a cleaning roller,
This is to remove toner when it adheres to the pressure roll 19.

In the example shown in FIG. 5, the intermediate transfer belt 15,
Since the toner and transfer material are heated together, it is possible to lower the heating temperature required for each of them, making it unnecessary to excessively heat each of them, and reducing the amount of heat that escapes. In addition to the fact that the heat utilization rate can be suppressed and the overall heat utilization rate can be significantly improved, the total energy consumption can be significantly reduced. Furthermore, it becomes possible to transfer and fix toner images at high speed. In addition, the intermediate transfer belt 15
Since the toner image carrier 11 is not heated excessively, the toner image carrier 11
Even if the material has a basic property of being sensitive to heat, such as a photoconductive photoreceptor, it does not impede its good properties, or is a part of the material components of the intermediate transfer belt 15. It is possible to prevent problems such as adhesion of toner image carrier 11 to the intermediate transfer belt 11, and the durability of the intermediate transfer belt 15 can be maintained for a long period of time since the intermediate transfer belt 15 is not heated to high temperatures or exposed to severe temperature changes. Alternatively, the heat resistance conditions required for the material of the intermediate transfer belt 15 can be relaxed, the selection range of materials can be expanded, and costs can be reduced. Further, the toner is not heated excessively, and image blurring or offset phenomena due to excessive fluidity of the toner do not occur. In addition, the transfer material is not excessively heated, thermal deformation and wrinkles of the transfer material do not occur, and of course, there is virtually no risk of fire.

FIGS. 6 and 7 show a recording apparatus in which the intermediate transfer body is of a roll type, and parts common to those in the above-described example are given common reference numerals and explanations are omitted.

In this example, a pressure roll 19 is brought into pressure contact from below with an intermediate transfer roll 25 having an adhesive layer such as silicone rubber as a transfer layer on a metal roll base, and both rolls 25 and 19 are heated by a heater 25A as described above. , 19A are built in, respectively.

A method using such an intermediate transfer roll has the advantage that the structure is simpler than the intermediate transfer belt method, and the temperature of the roll can be easily controlled.

A transfer fixing area C is formed on the circumferential surface of the pressure roll 19.
In the same manner as described above, a plurality of heat-resistant tapes 5 are pressed along the transfer paper feeding direction, and the transfer paper 14 is preheated by the heat of the roll 19. Both ends of the tape 5 are fixed and held by a support rod 26.

FIG. 8 shows a modification of FIG. 4, in which the heat-resistant tape 5 presses the transfer paper 14 against the pressure roll 19.
is endlessly spanned by a roller 29 that follows (or is fixed to) the roll 19. If the tape 5 is allowed to rotate endlessly in this way, it is convenient because the paper can be fed more smoothly.

FIG. 9 shows another embodiment of the present invention, and shows a pressure contact member 34 having protrusions 35 that intermittently contact the transfer paper 14 instead of using a heat-resistant tape. This pressure contact member 34 desirably has the following features:
It is made of a flexible heat-resistant film that can be deformed to follow the circumferential surface of the roll 19, and by contacting the transfer paper 14 only with the protrusion 35, friction between the two is reduced, eliminating paper jams, and heating the paper. is also fully possible.

Although the present invention has been illustrated above, the embodiments described above can be further modified based on the technical idea of the present invention.

For example, the arrangement pattern of the heat-resistant tape or pressure-welding area described above may be changed in various ways. The present invention is of course applicable to other recording devices than the above-mentioned recording apparatus.

[Brief explanation of drawings]

FIG. 1 is a plan view of a transfer paper heating device according to a reference example of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a plan view of a transfer paper heating device according to another reference example of the present invention. 4 is a sectional view of a transfer paper heating device according to an embodiment of the present invention, FIG. 5 is a schematic diagram of a recording apparatus incorporating the heating device of FIG. 4, and FIG. 6 is a diagram showing another embodiment of the present invention. A schematic diagram of the main parts of a recording device incorporating a heating device according to an example, FIG. 7 is a left side view of FIG.
The figure is a cross-sectional view of a transfer paper heating device according to still another embodiment of the present invention, and FIG. 9 is a cross-sectional view of a transfer paper heating device according to still another reference example of the present invention. In addition, in the symbols shown in the drawings, 1...
... Hot plate, 4, 34 ... Pressure member, 5 ... Heat-resistant tape, 7 ... Tape presser, 9 ... Conveyance roller, 1
1... Photosensitive drum, 13... Developing section, 14...
Transfer paper, 15...Intermediate transfer belt, 17...Heating roll, 17A, 19A, 25A...Heater,
19...pressure roll, 25...intermediate transfer roll,
35... Projection portion, A... Press transfer area, B... Intermediate transfer member heating area, C... Transfer fixing area, T...
This is a toner image.

Claims (1)

[Scope of Claims] 1. In a recording device that transfers a toner image on an image carrier to an intermediate transfer member and then transfers and fixes the toner image onto a moving sheet member, while the moving sheet member is brought into contact with the heating member, In a heating device for a moving sheet of a recording apparatus configured to transfer and fix a toner image on the intermediate transfer member onto the heated moving sheet by heating and conveying the heated moving sheet, A pressure contact roll that rotates and has a circumferential surface made of silicone rubber, is provided with a pressure contact member that presses the moving sheet body against the heating body, and the pressure contact member is flexible and rotates around the heating body. A heating device for a movable sheet body, comprising a heat-resistant band-like body having a coefficient of friction smaller than that of a surface and intermittently stretched in a direction orthogonal to the moving direction of the movable sheet body to constitute a pressure contact part.