JPH02284177A - Manufacture of endless resin film belt for electrostatic carrier transfer device - Google Patents

Abstract

PURPOSE:To equalize electric characteristics of the joint of the endless belt to those of the other parts of the belt and to enable uniform paper conveyance and transfer by overlaying one end of the resin film belt on the other end with each end having electrodes inside, and heat pressing both ends, while cooling their vicinities. CONSTITUTION:One end of the resin film belt 40 is overlaid on its other end with each end having the electrodes 42' insides and both ends are heat pressed, while their vicinities are cooled. The resin film 40 is made of a thermoplastic resin and can be heat pressed in the ends and to form the joint having sufficient mechanical strength by applying heat and pressure on the overlayed part, thus permitting the electric characteristics of the joint to be not different from the other parts and attraction of papers and image transfer to be uniformly executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing an endless resin film belt used in an electrostatic transfer transfer device.

2. Description of the Related Art In image forming apparatuses such as electrophotographic copying machines, an image carrier (
Represented by a photoreceptor. ) A common method for transferring the toner image formed on a transfer material (typically paper) is to transport the paper over the toner image and simultaneously charge the paper from the back side to electrostatically attract the toner. It is true. especially,
The transfer method, in which the paper is once supported on a transfer drum that is driven to rotate in synchronization with the photoreceptor, is mainly used in color copying machines because it enables multiple transfers to the paper. .

There are two ways to support the paper on the transfer drum, such as a mechanical gripping mechanism such as a gripper, and a method using electrostatic adsorption. Therefore, it is possible to reduce the distance between sheets regardless of the size of the sheets in the longitudinal direction, which has the advantage of increasing the copying speed accordingly.

FIG. 3 is a diagram illustrating a conventional electrostatic transfer transfer device that embodies a method of supporting paper on a transfer drum by electrostatic adsorption. 2 is a photoreceptor, which sends a toner image T obtained by being developed by a developing device (not shown) to a transfer position. Reference numeral 4 denotes a transfer drum that is rotatably supported so as to contact or be close to the surface of the photoreceptor 2 through the paper at the transfer position. As shown in plan views in FIGS. 4 and 5, respectively, a resin film belt 6 formed in an endless shape and a plurality of electrodes 8a, 8b formed alternately at regular intervals inside the resin film belt 6. and a support 10 made of an insulator that fixes each of these electrodes 8a, 8b to the resin film belt 6.

Note that the width of the support 1O is made smaller than the width of the resin film belt 6, so that the electric currents i8a and 8b are alternately exposed inside the resin film belt 6, and each of them receives power from a different power supply brush. It is now possible to receive. Transfer brushes 12a, 12b and suction brush 14a are provided inside the transfer drum 4 to perform transfer and paper suction.

14b, 16a, and 16b are fixed.

FIG. 6 is a power supply connection diagram for each brush. Transfer brushes 12a and 12 that slide on the electrodes 8a and 8b at the transfer position
b is connected to the positive side of the power supply 18 via the switch 20, and the negative side of the power supply 18 is grounded. The suction brushes 14a and 16a that slide on the electrode 8a at the paper transport position other than the transfer position are grounded, and the suction brushes 14b and 16a that slide on the electrode 8b at the paper transport position are also grounded.
6b are connected to the power supply 2 via switches 24 and 28, respectively.
2.26, and the negative sides of the power supplies 22 and 26 are grounded.

The operation of the electrostatic transfer transfer device having the above configuration will be explained.

The paper 32 placed on the paper feed tray 30 is sent out at a predetermined timing by the rotation of a feed roller 34 that is pivotally supported so as to come into contact with the upper surface of the paper 32. When the leading edge of the paper reaches the vicinity of the transfer drum 4, the switch 24 is turned on, and the output voltage of the power supply 22 increases to 1 through the electrode 14°b.
The electric field applied to the second electrode 8b and generated between the electrodes 8a and 8b causes the paper and the resin film belt 6 to be charged with different polarities, so that they exert an attractive force on each other. When the paper supported on the surface of the transfer drum 4 reaches the vicinity of the transfer area in synchronization with the rotation of the transfer drum 4, the switch 20 is turned on.
A DC voltage is applied to both electrodes 8a and 8b, and the paper is charged to the opposite polarity to the toner image T, and the toner image T on the photoreceptor 2, which rotates at the same peripheral speed as the paper, is electrostatically attracted and transferred. is executed. At this time, a DC voltage is applied to the suction brushes 14b and 16b located downstream of the transfer brush 12b, and if this copy is a full-color copy, the paper that has been transferred with the first color is It is designed to be continuously supported by the transfer drum. Transfers using the second and third colors are performed in the same manner, and when three or four transfers are completed, the switch 28 is turned off, and the paper is peeled off from the transfer drum 4 by the peeling claw 36 and placed on the conveyor belt 38. Sent out.

In the case of monochrome copying, the switch 28 is always turned off, and the paper is ejected every time - times of transfer are completed.

However, with the above configuration, when the paper is withdrawn, the plurality of electrodes 8a and 8b are always at the same potential, and the paper being transported or the semiconductive resin film belt 6 is partially charged. When performing the transfer at the transfer position, the high density areas are
A low part will appear. In order to avoid this phenomenon (hereinafter referred to as electrode pattern), a configuration as shown in FIG. 7 has been proposed.

In this conventional example (FIG. 7), in place of each electrode in the laminated structure shown in FIG. Power feeding brushes 9a and 9b are arranged to alternately slide on the exposed portions on both sides.

Assuming that the brush 9a is grounded and a voltage is applied to the brush 9b, looking at the connection state of each electrode 7, as the resin film belt 6 goes around, the voltage application and the connection to the ground part alternate. Since the process is repeated, each electrode is not always at the same potential, which prevents charge from accumulating on the resin film or paper, and eliminates the electrode pattern.

On the other hand, as a method for manufacturing a resin film belt, the following method has conventionally been generally implemented.

That is, by screen printing using silver paste,
An endless resin film belt was obtained by forming a plurality of electrodes at regular intervals on one side of a resin film and connecting the ends of the resin film with the electrode forming surface facing inside. In addition to supporting the resin film belt thus obtained as a transfer drum by supporting it on a support drum as in the conventional example described above, the resin film belt can be directly attached to a pair of rollers without being supported by a support drum. It is sometimes used rolled up.

Problems to be Solved by the Invention As methods for connecting the ends of resin films in order to form endless resin film belts, methods using adhesion and methods using thermocompression bonding have been implemented or proposed. This connection section is required to meet the following requirements.

(a) Volume resistivity (ρ) and dielectric constant (
The electrical characteristics such as ε) shall be the same as those of the parts other than the connecting parts. This is because if the electrical characteristics of the connecting portion are unique, paper conveyance and transfer cannot be performed uniformly in the circumferential direction of the resin film belt.

(b) There shall be no damage to the electrodes at or near the connecting part. This is because if the electrode is damaged, not only will it be impossible to apply an electric field well, but also sparks will be generated when power is supplied to the damaged part, which may cause the resin film to burn.

(c) There shall be no difference in level at the connecting part. If there is a step,
This is because when the stepped portion collides with the photoreceptor, the photoreceptor etc. may vibrate due to the impact, which may cause disturbances in the written image.

Conventionally, the method using thermocompression bonding can satisfy the requirements (a) and (c), but when heating the resin film, wrinkles may occur near the connecting portions and the electrodes may peel off. Yes, it was not possible to satisfy the request in (b). On the other hand, if the adhesive method is used, requirement (B) can be satisfied, but since there is a solidified adhesive in the connecting part and its electrical properties are generally different from resin films, requirement (B) cannot be met. I couldn't be more satisfied. Further, since it is necessary to provide an adhesive margin, requirement (c) is also not satisfied.

The present invention was created in view of these circumstances, and aims to provide a method for manufacturing an endless resin membrane belt that can simultaneously satisfy the requirements (a), (b), and (c) above. There is.

Means for Solving the Problem The above-mentioned technical problem is solved by forming a plurality of electrodes at regular intervals on one side of a semiconductive strip-shaped resin film made of thermoplastic resin.
This problem is solved by the method of the present invention, in which the opposing edges of the band-shaped resin films are overlapped with the electrodes on the inside, and the edges are bonded together by thermocompression while cooling the periphery.

Function: In the method of the present invention, the band-shaped resin film is formed from a thermoplastic resin in order to enable thermocompression bonding of the edges of the band-shaped resin film. That is, in the case of a band-shaped resin film made of thermoplastic resin, by applying heat and pressure to the overlapped portion, a connecting portion having sufficient mechanical strength can be formed. According to thermocompression bonding, the electrical characteristics of the connecting portion do not differ from the electrical characteristics of the portion other than the connecting portion.

In addition, in order to improve the mechanical strength of the connection part, it is free to use an adhesive in an amount that does not change the electrical characteristics.

Furthermore, in the method of the present invention, the reason why the surrounding area is cooled during thermocompression bonding is to prevent wrinkles from forming in the surrounding area due to the thermal influence of thermocompression bonding.

As described above, according to the present invention, (a), (b), and (c)
It becomes possible to simultaneously satisfy the requirements of

Example Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a diagram for explaining the process of forming electrodes on the resin film. First, as shown in FIG. 4A, a plurality of electrodes 42 are formed at regular intervals on the surface of a semiconductive resin film 400. The semiconductive resin film 4o is made of a thermoplastic resin such as acrylic, vinyl chloride, polyester, or polypropylene and made semiconductive by containing an appropriate amount of an antistatic agent such as carbon black. Further, as a method of forming the electrode 42,
A method of forming an electrode containing silver or the like as a main conductive component by screen printing, a method of forming a copper electrode by etching, and forming a nickel film thereon to prevent wear can be used.

Next, as shown in FIG. Apply pressure from both sides. By doing this, the electrode 42, which hardly undergoes plastic deformation, is buried in the resin film 40, and as shown in FIG.
An electrode 42' is formed having its surface coplanar with the surface of 0. The reason why the electrodes are buried in the resin film is to prevent the electrodes from being worn out due to rubbing against the brush during brush power supply.

FIG. 1 is a process diagram for forming an endless resin film belt with embedded electrodes as described above. First, as shown in Figure (a), the opposing edges of the resin film belt are overlapped with the electrode 42'' forming surface inside, and
This overlapping portion is thermocompressed using a hot press 46, 46. Reference numerals 48 and 50 denote coolers through which a coolant such as water flows, which cools the vicinity of the thermocompression bonded portion during thermocompression bonding to prevent wrinkles from forming in the resin film 40. Since the vicinity of the thermocompression bonding is cooled in this manner, the vicinity thereof is prevented from being plastically deformed and wrinkled due to heat transfer from the thermocompression bonding portion, and there is no fear that the electrode 42' may peel off. Furthermore, since thermocompression bonding is performed, the connecting portion is plastically deformed and no step is formed, as shown in FIG. 2(b). If a difference in level occurs due to some inconvenience, it is best to remove it. Therefore,
As shown in Figure (C), when the endless resin film belt is supported on the support drum 54, the thickness tl of the resin film belt at the thermocompression bonded portion and the thickness t2 at the portion other than the thermocompression bonding portion are approximately equal to each other. They can be the same.

In this way, according to this embodiment, the thickness of the endless resin film belt can be made uniform in the circumferential direction, so that in an electrostatic transfer transfer device configured using this resin film belt, Paper can now be picked up from any position, improving processing speed. In addition, since there is no step difference in the thermocompression bonding part, there is no risk of vibration occurring in the photoreceptor drum when the transfer drum and photoreceptor drum are in contact with each other, and image distortion is prevented, especially in the case of a digital copying machine. .

Effects of the Invention As detailed above, according to the present invention, (a) and (b) are achieved.
It is possible to provide a method for manufacturing an endless resin film belt for an electrostatic withdrawal transfer device that can simultaneously satisfy the requirements (c) and (c).

[Brief explanation of drawings]

FIG. 1 is an embodiment diagram of the present invention, and is a configuration diagram when forming a resin film belt in an endless shape. FIG. 2 is an embodiment diagram of the present invention, in which electrodes are formed on the resin film. The process diagrams and FIGS. 3 to 7 are diagrams for explaining the prior art. 48.50...Cooler. Applicant: Fuji Xerox Co., Ltd. Agent: Patent Attorney Ko Matsumoto 40... Resin film, 4242°... Electrode, 44.46... Heat press, (b) Figure ↓ (b) ( C) Figure b Figure B 0 ~ ~

Claims (1)

[Scope of Claims] A plurality of electrodes are formed at regular intervals on one side of a semiconductive belt-shaped resin film made of thermoplastic resin, and the mutually opposing edges of the belt-shaped resin film are overlapped with the electrodes inside. A method of manufacturing an endless resin film belt for an electrostatic conveyance transfer device, characterized in that the edges are bonded together by thermocompression while cooling the periphery thereof.