JPH02181773A - Attaching method of transferring material supporting sheet to transferring drum and transferring material supporting sheet - Google Patents

Abstract

PURPOSE:To improve precision of transferring position by fixing spacers attached freely attachable/detachable to the inner surface of both edge parts of the transferring material supporting sheet to a frame body annular part, and taking away the spacers after the transferring material supporting sheet is fixed to the frame body annular part. CONSTITUTION:The spacers 12-1, of the same size in a strip shape, are attached attachable/detachable to symmetrical positions of the inner surface of both edge parts of the transferring material supporting sheet 12. Because there is sufficient length and thickness in the spacers 12-1 to respond to the prescribed slack amount, when the spacers 12-1 are taken away after hanging hooking holes 12-2 of the transferring material supporting sheet 12 to a multiple number of hanging hooks 11-2 provided on a connecting part 11 of the frame body, winding around the annular part with the inner surface of the spacers 12-1 abutted without any space left to the outer surface of the frame body annular part 10, and adhering and fixing an end tip part to the frame body connecting part 11 by adhesive tape 12-4, a prescribed slack is formed on the transferring material supporting sheet 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for attaching a transfer material support sheet to a transfer drum used in a transfer device of an image forming apparatus such as an overlapping transfer type color copying machine, and the transfer material support sheet.

As shown in FIG. 9, a conventional color copying machine using an electrostatic photographic process has color separation filters 2B, 2G, and 2R of heavy, green, and red color separation filters 2B, 2G, and 2R and a yellow filter 2 on one photoreceptor drum 1.
．． The color-separated light image of the document 3 is exposed through Y to form four types of latent images, and each latent image is transferred to yellow, magenta, cyan, and black developing devices 4Y arranged around the photoreceptor drum 1. , 4M.

The four-color toner image obtained by developing with 4C and 4BK is fed from a paper feed section 6 to a position A onto a transfer drum 5 that is in contact with the photoreceptor drum 1 and rotates synchronously at the same linear speed. The transfer paper S is superimposed and transferred onto the rolled transfer paper S by the action of the transfer charger 7, and after the completion of four transfers, the transfer paper is separated from the transfer drum 5 by the separating claw 8 at part B, and then transferred by the fixing device 9. A color copying machine using a so-called color separation image superimposition transfer system in which a color copy is obtained by fixing is well known.

As shown in FIG. 10, the above-mentioned transfer drum includes a frame body made of metal such as aluminum, consisting of annular parts 10 at both ends of the drum and a connecting part 11 connecting these parts, and a drum rotating The front end edge and the rear end of the frame are connected to the connecting part 1 of the frame.
1 and a dielectric flexible transfer film 12 wound around the frame so that the side edges thereof are brought into contact with the outer peripheral surface of the frame and formed into a hollow cylindrical shape. A configuration in which a clamper 13 for gripping the leading edge of the transfer sheet S fed from the sheet feeding section 6 is provided in the connecting section 11 of the sheet feeding section 6 is widely used. For example, the transfer film 12 has a thickness of 75 to 150 μm.
Generally, a polyethylene terephthalate film (trade name: Mylar) or the like is used, and the transfer paper S fed from the paper feed section is gripped at the leading end by a clamper 13.
Transfer film 12 charged by charger 14
The four color toner images are electrostatically attracted to the transfer drum 5, are tightly attached to the transfer drum 5 without shifting, rotate integrally with the transfer drum, and the four color toner images are superimposed and transferred without shifting.

In the overlapping transfer type transfer device having the above configuration, it is important that the transfer paper and the transfer film supporting the transfer paper are in close contact with each other without any gaps at the transfer position by the transfer charger. If there is a gap between the transfer paper and the transfer film, a dielectric polarization phenomenon will occur and good transfer will not be possible.

In order for the transfer paper and the transfer film to always be in close contact with each other without any gaps, the transfer film needs to be attached to the frame in a cylindrical shape so that there are no folds, irregularities, twists, etc.

However, as mentioned above, the transfer film is polyethylene T
Since it is a thin film such as phthalate, once it is installed by the manufacturer, it cannot be used until the end of the machine's lifespan, and it will need to be replaced after a certain number of copies have been made.

Conventionally, the method of attaching the transfer film to the frame was to fix the front and rear ends of the transfer film to the connecting part of the frame, and to attach the both sides to the outer circumferential surface of the annular part of the frame with adhesive tape, fixing the four circumferences. What I learned is what I learned.

This method requires considerable skill to apply the transfer film so that it forms a cylindrical shape without folds or twists. However, as copiers and printers have become more popular in recent years, users are now required to replace the transfer film manually, and in such cases it is important to make sure that it can be installed easily and correctly. It won't happen.

Also, the frame of the transfer drum is not machined into a perfectly precise cylinder, so if the transfer film is tightly attached with all four circumferences fixed to the frame, the circumference of the transfer paper and photoreceptor drum will be distorted. A slight deviation occurs between the two surfaces. The thickness of the lines in some drawings is about 20 μm, so for example, if five color toner images of yellow, cyan, and magenta are superimposed to produce black, if the three color toner images are shifted by 20 μm from each other, then , the line color on the copy is not black,
This results in parallel lines of three colors: yellow, cyan, and magenta.

To solve this problem, only the front and rear ends of the transfer film are attached to the connecting part of the frame, and both edges in the transport direction are left free.
For example, Japanese Patent Application Laid-Open No. 56-57069 shows that it is sufficient to allow a slight slack in the transport direction and to support the movable movement.
It is disclosed in the publication No.

This amount of slack has a large effect on transfer performance, and if the amount of slack is too large,
There are many variations in position depending on each color, which tends to result in a color-shifted image. Furthermore, if the amount of slack is too small, dents are likely to be formed in the transfer film, resulting in transfer omission. If the toner is pasted tightly without sagging, the contact width with the photoreceptor at the transfer position (width of the lobes) is small, resulting in toner loss and the like, resulting in a bumpy image.

However, the above-mentioned publication only states that the transfer film should be attached to the frame body in a loose manner so as not to sag, and a method that relies on such recommendations will have a large impact on transfer performance. It must be said that it is nearly impossible to accurately determine the amount of slack in the transfer film in the transport direction, especially when the user is reattaching the film.

In view of the above-mentioned drawbacks of the conventional method of attaching a transfer paper support sheet of a transfer drum used in an overlapping transfer type image forming apparatus, the present invention provides that a user of an image forming apparatus can attach a transfer paper support sheet of a transfer drum to a frame. Even if the transfer material support sheet is replaced, the transfer material support sheet can be pasted with high precision with a predetermined slight slack and without folds, twists, or unevenness. An object of the present invention is to provide a material support sheet.

In order to solve the above problems, the method for attaching a transfer material support sheet of the present invention has the following features: (a) Prior to attaching the transfer material support sheet to the frame, Spacers having a length and thickness corresponding to a predetermined amount of slack are removably attached to positions facing each other on the inner surfaces of both edges in the circumferential direction, and (b) the inner surfaces of the spacers are attached to the outer peripheral surface of the annular part of the frame. (3) Fix the front and rear edges of the transfer material support sheet to the connection part of the frame so that the transfer material support sheet is in contact with the transfer material support sheet without any gaps, and the spacer is then removed from the transfer material support sheet. According to the present invention, the transfer material support sheet is attached to the frame with a predetermined amount of slack in the circumferential direction.

In the transfer material support sheet attached to the frame by this method, a spacer having a length and thickness corresponding to a predetermined amount of slack is attached to the frame of the transfer material support sheet before being attached to the frame. When attached to the body, the transfer material support sheet is brought into contact with the outer surface of the protruding portion and the transfer material support sheet adjacent thereto at positions opposite to each other on the inner surfaces of both ends in the circumferential direction so as to protrude from the side edges of the transfer material support sheet. It is best to attach removable adhesive tape across the outside surface.

A spacer having a length and thickness corresponding to a predetermined amount of slack is detachably attached to the inner surface of both end edges of the transfer material support sheet, so that the inner surface of the spacer is attached to the outer circumferential surface of the annular part of the frame. The front and rear ends of the transfer material support sheet are fixed to the connection part of the frame so that they are in contact with each other without any gaps, and then the spacer is removed from between the transfer material support sheet and the frame, and the transfer material support sheet is fixed. A certain amount of slack will naturally occur.

Place the spacer in contact with the inner surface of the transfer material support sheet so that it protrudes from the side edge of the transfer material support sheet, and apply removable adhesive tape across the outer surface of the protruding portion and the outer surface of the transfer material support sheet. Once attached, the spacer can be easily removed by peeling off the adhesive tape from at least the outer surface of the transfer material support sheet after it is attached to the frame, and the transfer material support sheet will not move. Even if the adhesive remains on the transfer paper support sheet, it can be easily wiped off.

EXAMPLES Below, examples of the method and transfer paper support sheet of the present invention will be explained in detail based on the drawings.

FIG. 1 is a diagram showing the process of attaching a transfer paper support sheet (transfer film) to the transfer drum explained in FIG. 10 by the method of the present invention. Therefore, the same members will be described with the same reference numerals. FIG. 2 is a diagram showing the transfer film 12 before being attached to the frame. The end edge of the transfer film 12, which is the front end in the rotational direction when attached to the frame, has a hook hole 12-2 that is hooked to a hook 11-2 provided on the connecting portion 11 of the frame. Multiple tubes are drilled. Furthermore, strip-shaped spacers 12-1 of the same size are removably attached to the inner surfaces of both end edges at symmetrical positions. The length and thickness of the spacer 12-1 are as shown in Figures 1 and 3.
As shown in the figure, the inner surface of the spacer 12-1 is connected to the frame annular portion 1.
When the front and rear ends of the transfer film 12 are fixed to the frame connecting part 11 by making them come into contact with the outer circumferential surface of the transfer film 12 without any gaps, the stripper 12-1 is removed.
The dimensions are such that the transfer film 12 has a predetermined slack in the transport direction.

The transfer film 12 connects the hooking hole 12-2 to the connecting portion 1 of the frame.
1, the inner surface of the spacer 12-1 is brought into contact with the outer peripheral surface of the frame annular portion 10 without any gaps, and the spacer 12-1 is wound along the annular portion, The rear end portion is adhered and fixed to the frame connecting portion 11 with adhesive tape 12-4. After that, if the spacer 12-1 is removed, the transfer film 1
A predetermined slack is formed in 2.

The sliders 12-1 have the same size and are attached to both ends of the transfer film 120 at symmetrical positions, so if you carefully wrap them around the frame, there will be no twisting or folds. .

However, when pulling it manually, the pulling force on the left and right sides is often not uniform, making it more likely to be twisted or wrinkled. Therefore, as shown in FIGS. 4, 5, and 6, the transfer film 12
When attaching the transfer film 12 to the frame by drilling the retaining holes 12-5 for the tension spring 16 on both sides of the rear end, the holes 12-3 at the rear end of the transfer film 12 and the frame connecting part are formed. A tension spring 16 having a pre-calculated tension and direction of action is stretched between the hook part fixed to the hook part 11 and the transfer film is wound around the frame without twisting or folding. If the rear end edge of the transfer film 12 is then fixed to the frame connecting portion 11 with the adhesive tape 12-4, the transfer film is surely prevented from being wrinkled or twisted. .

First, the spacer 12-1 is removed after fixing the front and rear ends of the transfer film, but even if the spacer 12-1 is attached to the inner surface of the transfer film 12 with an adhesive that is easily peeled off, it cannot be pulled within the adhesive surface. It is difficult to peel off, the transfer film tends to shift easily, and if adhesive remains behind, it is very difficult to clean.

Therefore, as shown in FIGS. 7 and 8, the spacer 12-
1 protrudes outward from the side edge of the transfer film 12 and contacts the inner surface of the transfer film 12.
A removable adhesive tape 17 is pasted across the protruding portion and the adjacent outer surface of the transfer film 12.

By doing this, the spacer 12-1 is reliably held in contact with the inner surface of the transfer film 12 at a predetermined position, and the inner surface is brought into contact with the annular part of the frame, and the transfer film 12 is moved into the frame. It can be wound around. However, when removing the spacer, if the adhesive tape 17 is peeled off, the spacer 12-1 is not adhered to the inner surface of the transfer film, so it can be removed very easily, and no adhesive remains on the inner surface of the transfer film. . Note that it is possible to remove the spacer by simply peeling the adhesive tape from the transfer film.

Effects As described above, according to the present invention, the transfer film can be attached to the frame of the transfer drum with high precision and with a predetermined slack, so the transfer position accuracy is improved and a good image with no color shift etc. is obtained. You can get the image.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an example of a transfer drum to which a transfer film is attached by the method of the present invention, Fig. 2 is a perspective view of the transfer film, Fig. 6 is a sectional view of the transfer drum, Figs. 6 are similar views of other embodiments, FIGS. 7 and 8 are perspective views and sectional views showing other methods of attaching the spacer to the transfer film, and FIG. 1 is a side sectional view of an example of an image forming apparatus having a transfer drum to which the present invention is applied, and FIG. 10 is a perspective view showing the structure of the transfer drum. 1... Photosensitive drum 5... Transfer drum 10.
...Transfer drum frame annular part 11...Transfer drum frame connection part 11-2...Transfer film locking hook 12...Transfer film (transfer material support sheet) 12-1...Spacer 12 -2...Tip retaining hole 12-4...Adhesive tape 16...Tension spring 17...Adhesive chip,
z-1

Claims (4)

[Claims] (1) A frame body consisting of annular parts at both ends of the drum, a single connecting part connecting these parts and extending in the axial direction of the drum, and a front end part and a rear end part in the rotational direction of the drum connected to the frame body. fixed to the connecting part of the frame, and attached to the frame so that the side end is along the outer circumferential surface of the annular part of the frame and closes the opening formed by the annular part of the frame and the connecting part. A transfer material supporting sheet made of a wound dielectric flexible film is formed into a hollow cylindrical shape. is adsorbed and supported on the outer circumferential surface of the transfer material support sheet, rotates in contact with the photoreceptor drum, and toner images of different colors sequentially formed on the photoreceptor drum are sequentially superimposed on the transfer material. In the method of attaching the transfer material support sheet of the transfer drum to the frame body for transfer, (a) prior to attaching the transfer material support sheet to the frame body,
Spacers having a length and thickness corresponding to a predetermined amount of slack are removably attached to positions facing each other on the inner surfaces of both edges in the circumferential direction when attached to the frame of the transfer material support sheet, B) Fix the front and rear edges of the transfer material support sheet to the connection part of the frame so that the inner surface of the spacer contacts the outer peripheral surface of the annular part of the frame without any gaps so that the transfer material support sheet does not slacken. ) The transfer material support sheet is then attached to the frame with a predetermined amount of slack in the circumferential direction by removing the spacer from the transfer material support sheet. Installation method. (2) The method of fixing the front and rear edges of the transfer material support sheet to the connecting part of the frame in step (b) above is to fix the front and rear edges to the frame and then support the transfer material on both sides of the rear end. The tension spring is attached to the frame connection part through a tension spring having a preset tensile strength and direction of action line so as to follow the outer peripheral surface of the annular part on both sides of the frame without causing folds, twists, dents, etc. in the sheet. 2. The method for attaching a transfer material support sheet according to claim 1, wherein the transfer material support sheet is hung and fixed to the frame connecting portion over substantially the entire length of the rear end edge of the transfer material support sheet in this state. (3) The method of removably attaching the spacer to the inner surface of both edges of the transfer material support sheet in step (a) above is such that the outer surface of the spacer is attached to the inner surface of the transfer material support sheet so that the spacer protrudes from the side edge of the transfer material support sheet. A removable adhesive tape is pasted across the outer surface of the protruding portion of the spacer and the outer surface of the adjacent transfer material support sheet, and the spacer in step (c) above is used to support the transfer material. A claim characterized in that the method for removing the adhesive tape from the sheet includes peeling off at least the adhesive tape from the transfer material support sheet, and pulling out the spacer by holding the protruding portion of the spacer from the edge of the transfer material support sheet. 1. A method for attaching a transfer material support sheet according to 1. (4) A frame body consisting of annular parts at both ends of the drum, a single connecting part connecting these parts and extending in the axial direction of the drum, and a front end part and a rear end part in the rotational direction of the drum connected to the frame body. fixed to the connecting part of the frame, and attached to the frame so that the side end is along the outer circumferential surface of the annular part of the frame and closes the opening formed by the annular part of the frame and the connecting part. A transfer material supporting sheet made of a wound dielectric flexible film is formed into a hollow cylindrical shape. is adsorbed and supported on the outer circumferential surface of the transfer material support sheet, rotates in contact with the photoreceptor drum, and toner images of different colors sequentially formed on the photoreceptor drum are sequentially superimposed on the transfer material. In the transfer material support sheet of the transfer drum that is used for transferring images, a spacer having a length and thickness corresponding to a predetermined amount of slack is attached to the transfer material support sheet to support the transfer material before being attached to the frame. When the sheet is attached to the above-mentioned frame body, the transfer material support sheet is brought into contact with the inner surface of both ends in the circumferential direction at opposing positions protruding from the side edges of the sheet, and the outer surface of the above-mentioned protruding part and the transfer material adjacent thereto are A transfer material support sheet characterized in that a removable adhesive tape is attached across the outer surface of the transfer material support sheet.