JPH04303631A - Manufacture of intermediate endless belt and apparatus used therefor - Google Patents

Abstract

PURPOSE:To improve the superficial condition, circumferential length accuracy and thickness accuracy of an intermediate transfer endless belt. CONSTITUTION:A loading roller 3 is placed into a steel pipe 2 and on the outer part of the steel pipe 2, a thermoplastic sheet 1 formed into an endless belt shape is disposed such that the inner peripheral surface thereof is faces to the outer peripheral surface of the steel pipe 2 and on the outside of the thermoplastic sheet 1, a heat resistive sheet 7 is arranged which is of the type that the one surface faced to the thermoplastic sheet 1 is treated into a mirror surface and further a hot roller 4 is disposed on the other surface side of the heat resistive sheet 7. By the loading roller 3, the steel pipe 2 is put into press- contact with the inner peripheral surface of the thermoplastic sheet 1 from its inside and by the hot roller 4, the heat resistive sheet 7 is brought into press-contact with the outer peripheral surface of the thermoplastic sheet 1 from its outside and keeping the condition, the steel pipe 2, loading roller 3, and the hot roller 4 are rotated with result that the outer peripheral surface of the heat resistive sheet 7 is made softened and smoothened while forwarding it in the circumferential direction.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to an intermediate transfer endless belt for transferring a toner image formed on a photoreceptor to its own outer surface and retransferring it to copy paper in an electrophotographic copying machine or the like. The present invention relates to a manufacturing method and an apparatus used therein.

0002

[Prior Art] A full-color toner image formed on a photoreceptor is first transferred onto the outer peripheral surface of an intermediate transfer endless belt made of thermoplastic resin, and then transferred again to copy paper. A modern full-color electrophotographic copying machine is normally configured as shown in FIG. That is,
This electrophotographic copying machine includes an optical device 12 that guides light reflected from an original 11, a filter 13 that separates the reflected light from the original into three primary colors of red, green, and blue, and a belt-shaped photoreceptor 14 having photoconductivity. , a developing device 15, an intermediate transfer endless belt 17 that once transfers the toner image formed on the photoreceptor 14 onto its own outer peripheral surface before copying it onto copy paper 16, and a fixing device 1.
It has 8. More specifically, a charger 19 is provided near the starting end of the photoconductive belt-shaped photoreceptor 14, and three developing sections 15a to 15c are provided in the middle of the photoreceptor 14. It is being The belt-shaped photoreceptor 14 is charged by the charger 19 and then exposed to light reflected from the original projected from the optical device 12, so that an electrostatic latent image is formed thereon. In this case, as described above, the projection path of the optical device 12 that projects the reflected light of the original onto the photoreceptor 14 is arranged such that the reflected light of the original is red,
A filter 13 is provided that separates the light into the three primary colors of green and blue, and the separated primary color light is guided onto a belt-shaped photoreceptor 14 in order, for example, red first, then green, and so on, where each of the electrostatic charges Form a latent image. The developing device 15 includes three developing sections 15a,
15b and 15c, each containing toner of three colors corresponding to the separated three primary colors. The latent image formed by the color-separated light is
It is colored and developed with toner corresponding to that color. That is,
A colored toner image is formed for each color by the above three types of toner, and this is caused by the action of the primary transfer roller 20.
The toner images are sequentially transferred to the outer surface of the endless intermediate transfer belt 17 to form a full-color toner image on the endless intermediate transfer belt 17. In this way, the copying machine sequentially transfers colored toner images formed for each color onto copy paper 16, and instead of forming colored toner images on copy paper 16, the copying machine expands and contracts due to humidity, etc. A colored toner image is once formed on the endless intermediate transfer belt 17. Then, the toner image is retransferred onto the copy paper 16 supplied from the paper cassette 21 by the action of the secondary transfer roller 22. The retransferred full-color toner image is sent to the fixing device 18 as the copy paper 16 is transported and is fixed thereon, and the copy paper 16 with the toner image fixed thereon is transferred to the fixing device 18 and fixed thereon.
is sent out from the copying machine as shown by the arrow. 23 is a conveyor belt.

As described above, in the electrophotographic copying machine described above, toner is once transferred from the photoreceptor 14 to the intermediate transfer endless belt 17, and then the toner is transferred from the intermediate transfer endless belt 17 to the copy paper 16.
will be retranscribed. Therefore, in addition to the electrical resistivity of the semiconductor region (108 to 109 Ωcm), the intermediate transfer endless belt 17 is free from local irregularities, circumferential and axial lines, and wrinkles from the viewpoint of surface condition. , preferably the surface is a mirror surface, and from the viewpoint of circumferential precision, the circumferential length should have an accuracy of ±0.5 mm, for example, in the case of a diameter of 200 mm, so that the belt does not loosen when attached to the machine. , and from the viewpoint of thickness accuracy, in order to prevent local unevenness of contact with the photoconductor 14 and copy paper 16 during installation on the machine, for example, in the case of a thickness of 200 μm, the thickness should be ±±.
It is required to have an accuracy of 20 μm. However, when the intermediate transfer endless belt 17 is manufactured by blow molding, the surface condition in the axial direction is poor due to mold parting, and when manufactured by inflation molding, the accuracy of the circumferential length is poor. For this reason, the intermediate transfer endless belt 17 is manufactured by an extrusion molding method, particularly by an inside mandrel method which can obtain good circumferential length accuracy.

0004

[Problem to be solved by the invention] However, the thickness 5
When manufacturing a particularly thin intermediate transfer endless belt 17 with a thickness of 0 to 500 μm by extrusion molding, even if the above-mentioned inside mandrel method is used, uneven linear velocity of the extruded resin, uneven flow inside the extrusion mold, etc. The actual situation is that even slight fluctuations in the uneven take-up speed cause non-uniform circumferential length and thickness, making it impossible to obtain an endless intermediate transfer belt 17 that satisfies the above requirements. Furthermore, the extrusion molding method has a problem in that streaks such as die scars occur in the extrusion direction.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing an intermediate transfer endless belt with good surface condition, circumferential length accuracy, and thickness accuracy, and an apparatus used therefor.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a load roller inserted into a cylindrical body, and a thermoplastic sheet formed into an endless belt outside the cylindrical body.
The inner circumferential surface of the cylindrical body is arranged so as to face the outer circumferential surface of the cylindrical body, and a heat-resistant sheet having a mirror finish on one side facing the thermoplastic sheet is disposed outside the thermoplastic sheet. A heating roller is disposed on the other side of the sheet, the cylindrical body is pressed against the inner peripheral surface of the thermoplastic sheet from the inside by the load roller, and the heat-resistant sheet is pressed from the outside by the heating roller. It is pressed against the outer peripheral surface of the thermoplastic sheet, and in this state, the cylindrical body, the load roller, and the heating roller are rotated to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction, while softening and smoothing the outer peripheral surface. The first gist is a method for manufacturing an endless intermediate transfer belt,
A load roller is inserted into a thermoplastic sheet formed into an endless belt shape, and a heat-resistant sheet with one side facing the thermoplastic sheet mirror-finished is arranged outside the thermoplastic sheet,
A heating roller is disposed on the other side of the heat-resistant sheet, the loaded roller presses the thermoplastic sheet against the heat-resistant sheet from the inside, and the heating roller presses the heat-resistant sheet against the thermoplastic sheet from the outside. Pressed against the outer peripheral surface of the sheet,
The second gist is a method for manufacturing an intermediate transfer endless belt, in which the load roller and heating roller are rotated in this state to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction while softening and smoothing the outer peripheral surface thereof. , a cylinder, and
a thermoplastic sheet formed into an endless belt shape and disposed outside the cylindrical body so that its inner circumferential surface faces the outer circumferential surface of the cylindrical body; and a thermoplastic sheet disposed outside the thermoplastic sheet. a heat-resistant sheet with one side facing mirror-finished, a load roller inserted into the cylindrical body and pressing the cylindrical body from the inside against the inner circumferential surface of the thermoplastic sheet, and a load roller disposed on the other side of the heat-resistant sheet. A third intermediate transfer endless belt manufacturing apparatus includes a heating roller which presses the heat-resistant sheet against the outer circumferential surface of the thermoplastic sheet from the outside, and a rotating means which rotates the cylindrical body, the load roller, and the heating roller. In summary, there is a heat-resistant sheet disposed outside a thermoplastic sheet formed into an endless belt shape and having one side facing the thermoplastic sheet mirror-finished, and a heat-resistant sheet disposed on the other side of the heat-resistant sheet. A heating roller that presses the thermoplastic sheet from the outside, a load roller that is inserted into the thermoplastic sheet and presses the thermoplastic sheet against the heat-resistant sheet from the inside, and a rotating means that rotates the heating roller and the load roller. The fourth aspect is an apparatus for manufacturing an intermediate transfer endless belt.

[0007]

[Operation] That is, in the present invention, a load roller is inserted into a cylindrical body, and a thermoplastic sheet formed in the shape of an endless belt is placed outside the cylindrical body so that its inner circumferential surface faces the outer circumferential surface of the cylindrical body. A heat-resistant sheet with mirror finish on one side facing the thermoplastic sheet is provided outside the thermoplastic sheet, a heating roller is provided on the other side of the heat-resistant sheet, and a heat roller is provided on the other side of the heat-resistant sheet. The cylindrical body is pressed against the inner peripheral surface of the thermoplastic sheet from the inside by the heating roller, and the heat-resistant sheet is pressed against the outer peripheral surface of the thermoplastic sheet from the outside by the heating roller, and in this state, the cylindrical body is pressed against the inner peripheral surface of the thermoplastic sheet from the inside. , a load roller and a heating roller are rotated to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction while softening and smoothing the outer peripheral surfaces thereof. In addition, a load roller is inserted into a thermoplastic sheet formed into an endless belt shape, and a heat-resistant sheet whose one side facing the thermoplastic sheet is mirror-finished is placed outside the thermoplastic sheet. A heating roller is disposed on the other side, the thermoplastic sheet is pressed against the heat-resistant sheet from the inside by the load roller, and the heat-resistant sheet is pressed from the outside by the heating roller to the outer peripheral surface of the thermoplastic sheet. In this state, the load roller and heating roller are rotated to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction, while softening and smoothing the outer peripheral surfaces thereof. Therefore, after forming a thermoplastic sheet into a cylindrical shape using an extrusion method or the like and processing it into an endless belt shape, the surface of the thermoplastic sheet can be smoothed to improve the surface condition.
An intermediate transfer endless belt with excellent circumferential length accuracy and thickness accuracy can now be obtained, and by using this intermediate transfer endless belt, an excellent effect is achieved in that images without toner filming or the like can be obtained. Moreover, since the thermoplastic sheet is smoothed using the mirror surface formed on the heat-resistant sheet, new heat-resistant sheets are successively fed between this thermoplastic sheet and the heating roller, and the new mirror surfaces are pressed into contact with the thermoplastic sheet one after another. This makes it possible to obtain an intermediate transfer endless belt with excellent surface condition, circumferential length accuracy, and thickness accuracy even after long-term use.

Next, the present invention will be explained in detail based on examples.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view of an endless belt surface straightening device showing an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts thereof. 1 is a sheet-like thermoplastic resin extruded into an endless belt shape by an extrusion molding machine (not shown), and this thermoplastic resin includes, for example, polycarbonate (PC).
), polypropylene (PP), etc. are used. 2 is a steel pipe, and the thermoplastic resin sheet 1 is coaxially disposed outside the steel pipe 2. The circumference of this thermoplastic resin sheet 1 is 100 to 103% of the circumference of the steel pipe 2, preferably 10% of the circumference of the steel pipe 2.
It is set between 0 and 101%. 3 is a load roller, the weight of which is set to 100 to 1000 g/cm. This load roller 3 is disposed in the axial direction within the steel pipe 2, and can be raised and lowered within the steel pipe 2 by a lifting device (not shown). That is, when not in use, the load roller 3 is moved upward, and when in use, it is moved downward. 4 is hot roller (heating roller)
The lower right side portion of the steel pipe 2 is brought into contact with the thermoplastic resin sheet 1 interposed therebetween, and the steel pipe 2 is rotated. In this example, the circumferential speed is set to approximately 0.5 m/min. In this hot roller 4, a heat-resistant elastic body 4b such as silicone rubber is formed on the outer circumferential surface of a core metal 4a that serves as a rotating shaft, and a heating means such as a nichrome wire is built inside the core metal 4a. The heat-resistant elastic body 4b is heated by the means. This heating temperature is 150-180℃ for PP,
In PC, it is set at 160 to 190°C. 4c is core metal 4
This is the rotating shaft part of a. 5 is the first cold roller;
The lower left side portion of the steel pipe 2 is brought into contact with the thermoplastic resin sheet 1 interposed therebetween, and the steel pipe 2 is rotated. The circumferential speed of the first cold roller 5 is set higher than the circumferential speed of the hot roller 4, so that it can absorb the elongation of the thermoplastic resin sheet 1 due to heating in the hot roller 4. 7 is a heat-resistant sheet, and polyimide film is used. Since this polyimide film has a heat shrinkage rate similar to that of the thermoplastic resin sheet 1 made of polycarbonate, wrinkles do not occur during surface straightening. The polyimide film 7 has a mirror-finished upper surface and a thickness of 125 μm. If the thickness is smaller than 125 μm, wrinkles will occur due to thermal expansion of the film, and if it is larger than 125 μm, the circumferential speed of the steel pipe 2 will be significantly slowed down. Also, 6 is the second
It is a cold roller and is used when separating the hot roller 4 from the steel pipe 2. 8 is a container for the polyimide film 7, and 9 is a collection body for the polyimide film 7.

In the above structure, first, the load roller 3 is disposed inside the steel pipe 2, the thermoplastic sheet 1 formed into an endless belt outside the steel pipe 2 is placed on the upper side, and the polyimide film 7 is placed on the lower side. and arrange it. Next, the load roller 3 is moved downward, and the load roller 3 presses the steel pipe 2 against the inner circumferential surface of the thermoplastic sheet 1 from the inside. Further, the hot roller 4 presses the thermoplastic sheet 1 and the polyimide film 7 onto the outer peripheral surface of the steel pipe 2 from the outside. In this state, the hot roller 4 and the first cold roller 5 are rotated in the same direction, and the steel pipe 2 and the load roller 3 are rotated in the same direction. As a result, the thermoplastic sheet 1 and the polyimide film 7 move along the outer peripheral surface of the steel pipe 2, and the outer peripheral surface of the thermoplastic sheet 1 is softened by heating from the hot roller 4, and the mirror-finished polyimide film 7 is moved along the outer peripheral surface of the steel pipe 2. The upper surface of the film 7 is smoothed.

After completing the above processing, the thermoplastic sheet 1
When removing the thermoplastic sheet 1, there may be adhesion marks from the hot roller 4 on the surface of the thermoplastic sheet 1, so peel it off while applying pressure little by little with the first cold roller 5 to avoid leaving any adhesion marks. Alternatively, the hot roller 4 may be lowered little by little to prevent the adhesion marks from forming on the surface of the thermoplastic sheet 1. Note that the polyimide film 7 can be cooled by the first cold roller 5 and easily peeled off from the thermoplastic sheet 1.

The intermediate transfer endless belt thus obtained has a smooth surface, and has good surface condition, circumferential length accuracy, and thickness accuracy. In addition, polyimide film 7
Since the polyimide film 7 is sent one after another, the mirror surface of the new polyimide film 7 can always be used for surface correction.

FIG. 3 is an explanatory diagram of an endless belt surface straightening device showing another embodiment of the present invention. In this endless belt surface straightening device, a thermoplastic resin sheet 1 and a polyimide film 7 are sandwiched between a load roller 3, a small-diameter hot roller 10, and a first cold roller 5, without using a steel pipe 2. The other parts are the same in structure as the above embodiment, and have the same effects.

In the above embodiment, the steel pipe 2 is used, but a mandrel may be used instead. Also,
In the above embodiment, the thermoplastic resin sheet 1 is disposed coaxially with the steel pipe 2, but it may be extruded and coated onto a mandrel.

Further, in the above embodiment, the hot roller 4 and the first cold roller 5 are used as the driving rollers for the steel pipe 2, but the invention is not limited to this, and either the hot roller 4 or the first cold roller 5 can be used. Only one of them may be used as a driving roller, or means other than the two rollers 4 and 5 may be used to rotate the steel pipe 2.

[0016]

As described above, in the present invention, a load roller is inserted into a cylindrical body, and a thermoplastic sheet formed in the shape of an endless belt is placed outside the cylindrical body so that its inner peripheral surface is that of the cylindrical body. A heat-resistant sheet is arranged so as to face the outer peripheral surface, and one side facing the thermoplastic sheet is mirror-finished, and a heat-resistant sheet is arranged outside the thermoplastic sheet, and a heating roller is arranged on the other side of the heat-resistant sheet. The cylindrical body is pressed against the inner peripheral surface of the thermoplastic sheet from the inside by the load roller, and the heat-resistant sheet is pressed against the outer peripheral surface of the thermoplastic sheet from the outside by the heating roller. In this state, the cylindrical body, the load roller, and the heating roller are rotated to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction, while softening and smoothing the outer peripheral surfaces thereof. Also,
A load roller is inserted into a thermoplastic sheet formed into an endless belt shape, and a heat-resistant sheet with one side facing the thermoplastic sheet mirror-finished is arranged outside the thermoplastic sheet,
A heating roller is disposed on the other side of the heat-resistant sheet, the loaded roller presses the thermoplastic sheet against the heat-resistant sheet from the inside, and the heating roller presses the heat-resistant sheet against the thermoplastic sheet from the outside. Pressed against the outer peripheral surface of the sheet,
In this state, the load roller and heating roller are rotated to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction while softening and smoothing the outer peripheral surfaces thereof. Therefore, after forming a thermoplastic sheet into a cylindrical shape using an extrusion method or the like and processing it into an endless belt shape,
The surface of the thermoplastic sheet can be smoothed,
An intermediate transfer endless belt with excellent surface condition, circumferential length accuracy, and thickness accuracy can now be obtained, and by using this intermediate transfer endless belt, an excellent effect can be obtained in that images without toner filming etc. can be obtained. Moreover, since the thermoplastic sheet is smoothed using the mirror surface formed on the heat-resistant sheet, new heat-resistant sheets are successively fed between this thermoplastic sheet and the heating roller, and the new mirror surfaces are pressed into contact with the thermoplastic sheet one after another. This makes it possible to obtain an endless intermediate transfer belt with always excellent surface condition.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an endless belt surface straightening device showing one embodiment of the present invention.

FIG. 2 is an enlarged view of the main part thereof.

FIG. 3 is a sectional view of an endless belt surface straightening device showing another embodiment of the present invention.

FIG. 4 is a configuration diagram of a full-color copying machine incorporating an endless intermediate transfer belt.

[Explanation of symbols]

1 Thermoplastic sheet 2 Steel pipe 3 Load roller 4 Hottu roller 7 Heat-resistant sheet

Claims (4)

[Claims] [Claim 1] A load roller is inserted into a cylindrical body, and a thermoplastic sheet formed into an endless belt shape is disposed outside the cylindrical body so that its inner circumferential surface faces the outer circumferential surface of the cylindrical body. and disposing a heat-resistant sheet outside the thermoplastic sheet, one side facing the thermoplastic sheet having a mirror finish,
A heating roller is disposed on the other side of the heat-resistant sheet, the loaded roller presses the cylindrical body from the inside to the inner peripheral surface of the thermoplastic sheet, and the heating roller brings the heat-resistant sheet to the outside. The cylindrical body, the load roller, and the heating roller are rotated in this state to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction, while softening and smoothing the outer peripheral surface of the thermoplastic sheet. 1. A method for producing an endless intermediate transfer belt, the method comprising: [Claim 2] A load roller is inserted into a thermoplastic sheet formed into an endless belt shape, and a heat-resistant sheet having a mirror finish on one side facing the thermoplastic sheet is disposed outside the thermoplastic sheet. A heating roller is disposed on the other side of the heat-resistant sheet, the loaded roller presses the thermoplastic sheet against the heat-resistant sheet from the inside, and the heating roller presses the heat-resistant sheet against the thermoplastic sheet from the outside. The intermediate material is pressed against the outer circumferential surface of the thermoplastic sheet and the heat-resistant sheet by rotating the load roller and heating roller in this state to feed the thermoplastic sheet and the heat-resistant sheet in the circumferential direction while softening and smoothing the outer circumferential surface of the thermoplastic sheet and the heat-resistant sheet. A method for manufacturing an endless transfer belt. 3. A cylindrical body, a thermoplastic sheet formed into an endless belt shape and disposed outside the cylindrical body so that its inner circumferential surface faces the outer circumferential surface of the cylindrical body, and the thermoplastic sheet a heat-resistant sheet disposed outside and having one side facing the thermoplastic sheet mirror-finished; a load roller inserted into the cylindrical body and pressing the cylindrical body from the inside against the inner peripheral surface of the thermoplastic sheet; A heating roller disposed on the other side of the heat-resistant sheet and pressing the heat-resistant sheet against the outer peripheral surface of the thermoplastic sheet from the outside, and a rotating means for rotating the cylindrical body, the load roller, and the heating roller. Manufacturing equipment for intermediate transfer endless belts. 4. A heat-resistant sheet disposed outside the thermoplastic sheet formed into an endless belt shape and having one side facing the thermoplastic sheet mirror-finished, and a heat-resistant sheet disposed on the other side of the heat-resistant sheet and having a A heating roller that presses the sheet against the thermoplastic sheet from the outside, a load roller that is inserted into the thermoplastic sheet and presses the thermoplastic sheet against the heat-resistant sheet from the inside, and rotation that rotates the heating roller and the load roller. An apparatus for manufacturing an intermediate transfer endless belt, comprising: means.