JPH04303629A - Manufacture of intermediate transfer 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:Into the inner part of a steel pipe 2, a loading roller 3 is inserted and, on the outside 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 faced to the outer peripheral surface of the steel pipe 2 and further on the outside of the thermoplastic sheet 1, a hot roller treated into a mirror surface in its outer peripheral surface is arranged. By the loading roller 3, the steel pipe 2 is put into press-contact with the outer peripheral surface of the thermoplastic sheet 1 from the inside thereof and keeping this condition, the steel pipe 2, loading roller 3, and hot roller 4 are rotated for softening and smoothing the outer peripheral surface of the thermoplastic sheet 1 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.
A heating roller whose inner circumferential surface faces the outer circumferential surface of the cylindrical body, and a heating roller whose outer circumferential surface is mirror-finished is disposed outside the thermoplastic sheet. The body is pressed against the inner peripheral surface of the thermoplastic sheet from the inside, and the thermoplastic sheet is pressed against the outer peripheral surface of the cylindrical body from the outside by the heating roller, and in this state, the cylindrical body, the load roller, and the heating roller The first gist is a method for manufacturing an intermediate transfer endless belt in which the thermoplastic sheet is rotated to soften and smooth the outer peripheral surface while feeding the thermoplastic sheet in the circumferential direction. A load roller is inserted, a heating roller whose outer circumferential surface is mirror-finished is arranged outside the thermoplastic sheet, and the thermoplastic sheet is pressed against the outer circumferential surface of the heating roller from the inside by the load roller. The second gist is a method for manufacturing an intermediate transfer endless belt in which the load roller and the heating roller are rotated to feed the thermoplastic sheet in the circumferential direction while softening and smoothing the outer peripheral surface thereof. A thermoplastic sheet formed into a 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 inserted into the cylindrical body to heat the cylindrical body from the inside. a load roller that presses against the inner circumferential surface of the plastic sheet; a heating roller that is disposed outside the thermoplastic sheet and has a mirror-finished outer circumferential surface that presses the thermoplastic sheet from the outside against the outer circumferential surface of the cylindrical body; and the cylindrical body. , the third gist is an apparatus for producing an intermediate transfer endless belt, which is equipped with a rotating means for rotating a load roller and a heating roller. An intermediate transfer endless belt comprising a heating roller, a load roller inserted into the thermoplastic sheet and pressing the thermoplastic sheet against the outer peripheral surface of the heating roller from the inside, and a rotating means for rotating the heating roller and the load roller. The fourth gist is the manufacturing equipment.

[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 heating roller having a mirror-finished outer circumferential surface is disposed outside the thermoplastic sheet, and the cylindrical body is pressed against the inner circumferential surface of the thermoplastic sheet from the inside by the load roller; The thermoplastic sheet is pressed against the outer peripheral surface of the cylindrical body from the outside by the heating roller, and in this state, the cylindrical body, the load roller, and the heating roller are rotated to feed the thermoplastic sheet in the circumferential direction. The outer peripheral surface is softened and smoothed. In addition, a loaded roller is inserted into a thermoplastic sheet formed into an endless belt shape, and a heating roller whose outer circumferential surface is mirror-finished is arranged outside the thermoplastic sheet. is pressed against the outer circumferential surface of the heating roller from the inside, and in this state, the load roller and the heating roller are rotated to feed the thermoplastic sheet in the circumferential direction while softening and smoothing the outer circumferential surface. Therefore,
After forming a thermoplastic sheet into a cylindrical shape using extrusion molding and processing it into an endless belt, the surface of the thermoplastic sheet can be smoothed, resulting in excellent surface condition, circumferential length accuracy, and thickness accuracy. An endless intermediate transfer belt can now be obtained, and by using this endless intermediate transfer belt, an excellent effect can be obtained in that images without toner filming or the like can be obtained.

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

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of an endless belt surface straightening device showing one embodiment of the device 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 using an extrusion molding machine (not shown), and examples of the thermoplastic resin used include polycarbonate (PC) and polypropylene (PP). 2 is a steel pipe, and the thermoplastic resin sheet 1 is coaxially disposed outside the steel pipe 2. The circumferential length of the thermoplastic resin sheet 1 is set to 100 to 103%, preferably 100 to 101%, of the circumferential length of the steel pipe 2. 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. Reference numeral 4 denotes a hot roller (heating roller), which contacts the lower portion of the steel pipe 2 via the thermoplastic resin sheet 1 and rotates the steel pipe 2. In this example, the linear speed is set to 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. Further, the hot roller 4 has its outer peripheral surface polished, and the surface is further coated with silicon to give it a mirror finish.
Prevents molten thermoplastic resin from adhering to the surface. 4c is a rotating shaft portion of the core bar 4a. A first cold roller 5 contacts the lower portion of the steel pipe 2 with the thermoplastic resin sheet 1 interposed therebetween, and rotates the steel pipe 2. Reference numeral 6 denotes a second cold roller, which can freely move forward and backward with respect to the outer circumferential surface of the steel pipe 2 (moveably in the direction shown by arrow A).
It is provided.

In the above structure, first, a load roller 3 is disposed inside the steel pipe 2, and a thermoplastic sheet 1 shaped like an endless belt is disposed outside the steel pipe 2. 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 against 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 moves along the outer circumferential surface of the steel pipe 2, and the outer circumferential surface of the thermoplastic sheet 1 is softened by heating from the hot roller 4, and the outer circumferential surface of the hot roller 4, which is mirror-finished, is heated. smoothed by . After the processing is completed, the second cold roller 6 pushes up the steel pipe 2 from the outside of the thermoplastic sheet 1, and the hot roller 4 is separated 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. Further, since the steel pipe 2 has a large diameter, the contact area between the steel pipe 2 and the hot roller 4 is large, and the accuracy of the thickness is further improved.

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, the steel pipe 2 is not used, and the thermoplastic resin sheet 1 is sandwiched between a load roller 3, a small-diameter hot roller 7, and the first cold roller 5. 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 7 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 7 or the first cold roller 5 can be used. Only one of them may be used as a driving roller, or means other than both 5 and 7 may be used to rotate the steel pipe 2.

Furthermore, in the above embodiment, the outer circumferential surface of the hot roller 4 is coated with silicone after being mirror-finished, but this is not limiting. It may be coated with a type of Teflon resin.

[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 heating roller is disposed so as to face the outer circumferential surface, and the outer circumferential surface is mirror-finished outside the thermoplastic sheet. the thermoplastic sheet is pressed against the outer peripheral surface of the cylindrical body 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 in the circumferential direction while softening and smoothing the outer peripheral surface of the thermoplastic sheet. In addition, a loaded roller is inserted into a thermoplastic sheet formed into an endless belt shape, and a heating roller whose outer circumferential surface is mirror-finished is arranged outside the thermoplastic sheet. is pressed against the outer circumferential surface of the heating roller from the inside, and in this state, the load roller and the heating roller are rotated to feed the thermoplastic sheet in the circumferential direction while softening and smoothing the outer circumferential surface. Therefore, after forming a thermoplastic sheet into a cylindrical shape using an extrusion method or the like and processing it into an endless belt, the surface of the thermoplastic sheet can be smoothed, and the surface condition, circumferential precision, and thickness can be improved. An intermediate transfer endless belt with excellent 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 or the like can be obtained.

[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 perspective 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

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. A heating roller having a mirror-finished outer peripheral surface is disposed outside the thermoplastic sheet, and the cylindrical body is pressed against the inner peripheral surface of the thermoplastic sheet from the inside by the load roller, and the heating roller is pressed against the inner peripheral surface of the thermoplastic sheet. Therefore, the thermoplastic sheet is pressed against the outer peripheral surface of the cylindrical body from the outside, and in this state, the cylindrical body,
A method for manufacturing an intermediate transfer endless belt, which comprises rotating a load roller and a heating roller to feed the thermoplastic sheet in the circumferential direction while softening and smoothing the outer peripheral surface of the thermoplastic sheet. 2. A loaded roller is inserted into a thermoplastic sheet formed in the shape of an endless belt, and a heating roller whose outer peripheral surface is mirror-finished is disposed outside the thermoplastic sheet, and the loaded roller causes the above-mentioned The thermoplastic sheet is pressed against the outer circumferential surface of the heating roller from the inside, and in this state, the load roller and the heating roller are rotated to feed the thermoplastic sheet in the circumferential direction while softening and smoothing the outer circumferential surface. A manufacturing method for a featured intermediate transfer endless belt. 3. A cylindrical body, a thermoplastic sheet formed into an endless belt shape and disposed outside the cylindrical body so that its inner peripheral surface faces the outer peripheral surface of the cylindrical body, and a thermoplastic sheet inside the cylindrical body. a load roller that is inserted and presses the cylindrical body from the inside against the inner circumferential surface of the thermoplastic sheet; and a load roller that is disposed outside the thermoplastic sheet and whose outer circumferential surface is mirror-finished and presses the thermoplastic sheet from the outside to the outer circumferential surface of the cylindrical body. a heating roller that presses against the
An apparatus for manufacturing an intermediate transfer endless belt, comprising: a rotating means for rotating the cylindrical body, a load roller, and a heating roller. 4. A heating roller disposed outside a thermoplastic sheet formed into an endless belt shape and having a mirror-finished outer peripheral surface; A manufacturing apparatus for an intermediate transfer endless belt, comprising: a load roller that presses against an outer circumferential surface; and rotation means that rotates the heating roller and the load roller.