JPS5850565A - Sheet member fixing method - Google Patents

Abstract

PURPOSE:To fix a sheet member without generating a hollow or a distortion, by fixing a sheet member held by a flexible film onto a sheet member fixed body having an opening, then, removing the flexible film. CONSTITUTION:A sheet member to be fixed, for instance, a mesh-like insulating screen 5 is stuck onto a flexible film 6 which has applied an adhesive substance on the surface at first, and a sheet member laminated substance is formed. The screen 5 of this laminated substance is set as the inside surface, the adhesive film 6 is set as the outside surface, and they are stuck uniformly along the circumference of a transfer drum 2, then, only the adhesive film 5 is peeled off from the transfer drum. In this way, the mesh-like screen 5 holding a satisfactory curved surface can be fixed onto the transfer drum, and by using the transfer drum constituted in this way, it is possible to obtain a transfer picture image which is free from blur, unevenness, and variation of color tone.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet member fixing method that makes it possible to satisfactorily fix a thin sheet member.

Conventionally, various types of transfer devices based on a corona transfer method have been proposed and put into practical use as devices for O-transferring a toner image formed on an image bearing member such as an electrophotographic photoreceptor to a transfer material such as plain paper. In particular, a transfer device that holds the transfer material on an insulated drum and applies transfer corona from the back side is extremely effective, as it can not only transfer a nest-colored toner image but also perform multiple transfers using multicolor toner. However, in practical conventional transfer devices, V-) a method of holding the member on an insulating drum, that is,
The method of attaching the transfer screen to the transfer drum was very inconvenient.

This will be explained below with reference to the drawings.

FIGS. 1 and 2 briefly explain the transfer device. In the figure, 1 is a photosensitive drum, 2 is a transfer drum, and 5 is a transfer charger.

In the apparatus shown in FIG. 2, a mesh insulating screen 5 is stretched over the opening of a cylinder 4 of the transfer drum to form a transfer drum 2. A transfer charger 6 on the back side of the transfer screen 5 applies corona discharge to the transfer drum. The transfer paper is electrostatically attracted to the surface of the screen 5, and the tner image on the photosensitive drum 1 is transferred to the transfer paper.

As the transfer screen used in the transfer drum, an insulating film having a volume resistivity of I x 1010 Ωscm or more is usually used. This is because if the resistance value is low, when transfer charging is performed, charge leaks, making it impossible to obtain the electric field strength necessary for transfer, and also preventing electrostatic attraction of the transfer paper. Further, the thickness of this insulating film needs to be at least 5 tones, preferably 207 tones or more. If it is less than that, sufficient volume resistivity cannot be maintained. When using such a thick insulating film as a transfer screen, in order to obtain good electrostatic adhesion to the transfer paper on the transfer screen! 1ooo
A high charging potential of V or higher must be applied. In addition, when a high charging potential is applied, when one transfer sheet separates from the transfer drum after transfer, discharge occurs, which tends to cause toner scattering and m-image disturbance.

In order to overcome the above-mentioned drawbacks, it is currently proposed to use a mesh insulating screen instead of using an insulating film.Using a screen having a mesh size of 0, i.e., 10" mesh or less, preferably 30 mesh or less. By doing so, it is intended to suppress the charging potential on the back side of the mesh screen due to transfer charging to a low level of approximately 2000 V or less, and to maintain the electrostatic attraction force of the transfer paper on the screen surface. By creating a mesh pattern, the electric field strength required for transfer and electrostatic adsorption is maintained, while the charging potential on the back side of the screen is kept below 2000 V.This reduces the charging potential when the transfer paper is separated from the transfer drum. Toner scattering - image disturbance can be prevented.

However, in the device configurations shown in Figures 1 and 2, because the transfer screen is stretched across the cylinder opening in an arc shape,
A transfer screen is required to have mechanical strength such as strength to maintain a curved surface or tensile strength, but when a mesh insulating screen is used as a transfer screen, it cannot be denied that the mechanical strength is inferior to that of an insulating film. More specifically, when attaching a mesh insulating screen to the cylinder opening, it is extremely difficult to maintain a uniform curved surface and precise roundness in terms of mechanical strength. Furthermore, the thickness of the screen must be as thin as possible as long as it maintains high insulating properties, since the thicker the screen, the higher the charging potential must be applied. accompanies.

The transfer drum is attached to the insulating film (similar to the method of attaching the mesh insulating screen to the front end of the cylinder opening directly, and attaching it along the circular axis of the transfer drum 10). Due to its pliability, there is a dent in the screen.

Distortion and wrinkles occur, and in monochrome development and transfer, distortion and indentation occur in the transferred image. Further, in multiple transfers, such as in the case of copying, changes in color tone and density unevenness occur.

In view of the above problems, the present invention provides a novel method for attaching a mesh screen to a transfer drum.

In the present invention, a sheet member is held on a flexible support film, the sheet member held by the flexible film is fixed on a sheet member fixing body having an opening, and then the flexible support film is fixed. The present invention relates to a method for fixing a sheet member, characterized in that the sheet member is removed.

The details of the present invention will be explained below using specific examples with reference to the drawings.

FIG. 6 is a reference diagram illustrating a state in which a sheet member (for example, a mesh insulating screen) 5 to be fixed in the present invention is first adhered and held on a flexible film 6 whose surface is coated with an adhesive substance. It is a private property.

In this way, a sheet member laminate is formed.

Next, as shown in FIG. 4, the screen 5 of this laminate is oriented toward the inner surface of the transfer drum 2, and the laminated adhesive film 6 is turned to the outer surface and is uniformly applied along the circumference of the cylinder 4 of the transfer drum. After that, only the adhesive film 6 is peeled off from the transfer drum S. In this way, a transfer drum having a mesh screen 5 as shown in the second diagram O is obtained. Moreover, at this time, the screen maintains a good curved surface.

The adhesive film used in the present invention must have flexibility so that it can behave in close contact with the mesh insulating screen, and rigidity that can maintain the curvature of the support surface of the transfer drum. This makes it possible to attach the flexible mesh-like insulating screen to the transfer drum uniformly and without dents, creases, creases, etc. along the curved surface and with precise roundness. The material of the adhesive film in the present invention is vinyl chloride, polyethylene, polyester, polystyrene, polyvinyl ethylene chloride, vinyl chloride 9F, etc. , polypropylene, and nylon. As for its thickness,
10 or more voices, preferably 50P or more are required. The adhesive substance has sufficient adhesion performance for O which holds the sheet member. The sheet member used in the present invention (for example, a mesh insulating screen) has a low resistance value even if it is thin. Materials such as high polyester, polycarbonate, triacetate, polypropylene, etc. are good. The thickness needs to be 10/I or more, preferably 50 tones or more. In particular, in the case of a mesh, the opening of the mesh should be considered.However, it goes without saying that the sheet 4 member of the present invention is not limited to only a mesh or a screen.

[Brief explanation of drawings]

Figure 1 is a side view illustrating a transfer device that can be manufactured using the method of the present invention, Figure 2 is a perspective view of a transfer drum, and Figures 5 and 4 are schematic diagrams illustrating the method of the present invention. FIG. 3 is a schematic diagram illustrating the process of laminating the sheet member and the support film, and FIG. 4 is a schematic diagram illustrating the process of fixing the laminate to the transfer drum. In the figure, 1 ink photosensitive drum, 2 ru transfer dots, 51 transfer charger, 4J cylinder rs 5' mesh insulation screen (sheet member), 6s adhesive film (flexible support film). Applicant Canon Co., Ltd. Agent Gi Marushima −ゝ? difference!・ 8 Sani Rinichi 4'. )? −

Claims (1)

[Scope of Claims] (1) A sheet member is held on a flexible support film, and the sheet member held on the flexible support film is fixed on a sheet member fixing body having an opening, and then, A method for fixing a sheet member, comprising removing a flexible support film. (2. In the invention set forth in claim 1, the flexible support film is provided with an adhesive layer to adhere and hold the sheet member on its surface. (6) A method for fixing a sheet member according to the invention as set forth in claim 1, wherein the sheet member is a mesh screen. (4) In the invention as set forth in claim 1, the sheet member fixing method is characterized in that the sheet member fixing body is a cylinder having an opening.