JPS6358387A - Transfer device - Google Patents

Abstract

PURPOSE:To securely prevent such a follow character that part of a copy that is blank around the center from being generated by making the moving speed of a photosensitive body different from the moving speed of transfer paper to which a toner image formed on the surface of a photosensitive body is transferred. CONSTITUTION:The photosensitive body 1 is charged electrostatically by an electrostatic charger 2 and exposed by an exposure part 3, so that an electrostatic latent image is formed on the photosensitive body 1. The electrostatic latent image on this photosensitive body 1 is visualized with toner by a development part 4 and this visualized toner image contacts transfer paper 6 sent from a paper feed part 5 and is fixed on the transfer paper 6 with an electric field. This transfer paper 6 is sent to a fixation part 8 and the toner image is fixed on the transfer paper 6. The moving speed of the photosensitive body 1 is different from the moving speed of the transfer paper 6 to which the image formed on the surface of the photosensitive body 1 is transferred, and consequently the generation of the follow character is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transfer device, and more particularly to a transfer device for transferring a toner image onto recording paper, such as an electrophotographic copying machine or various printers.

2. Description of the Related Art In general, an apparatus for transferring a toner image onto a transfer paper by bringing the toner image on a toner image support into contact with the transfer paper applies an electric charge to the back surface of the transfer paper by corona discharge. A so-called corona transfer method and a method in which a roll, drum, belt, etc. are brought into contact with the back side of transfer paper and a high potential is applied to these rolls, drums, belts, etc. are known.

Problems to be Solved by the Invention As drawbacks often seen in the conventional transfer method as described above, as shown in FIG. Near the edge d of the large-area image C, a phenomenon occurs in which a hollow character (hereinafter referred to as a hollow character) is partially but not collectively transferred.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transfer device that does not produce the above-mentioned hollow characters.

Ninth Means and Effects for Solving the Problems In a device in which a toner image formed on the surface of a toner image support through an exposure step and a development step is transferred to a transfer paper in a transfer section, movement of the toner image support. This transfer device prevents the occurrence of shallow characters by changing the moving speed of the transfer paper and transferring the toner image on the toner image support member to the transfer surface in the next state.

Embodiment FIG. 1 is a schematic diagram showing an example of the process of an electrophotographic copying machine, in which a photoreceptor 1 is charged by a charger 2 and exposed to light by an exposure section 3 to form an electrostatic latent image on the photoreceptor j. form.

This electrostatic latent image on the photoreceptor 1 is visualized by toner in the trench section 4, and this visualized toner image is sent from the paper feed section 5 and comes into contact with the transfer paper 6 at the transfer section 7. The image is transferred to the transfer paper 6 by an electric field.

This transfer paper 6 is then sent to a fixing section g, and the toner image is fixed on the transfer paper 6. Note that 9 is a cleaning section.

FIG. 2 shows the transfer paper conveyance means in the transfer section 7. As the transfer paper conveyance means, a belt 11 wound endlessly around a roll 10, 10 is used. is provided with a ninth electrostatic adsorption charging means 12 that attracts the transfer paper 6 fed from the paper feed section 5 to the belt 11, and a ninth electrostatic adsorption charging means 12 is provided on the transfer paper delivery side of the belt 11 to prevent the accumulation of charges. To prevent this, static eliminating means 13 is provided. The polarity of the charging means 12 for electrostatic attraction may be either positive or negative, and a counter electrode 14 is provided opposite to the charging means 12 for electrostatic attraction.

The efficiency of the charging means 12 is improved.

15 is a conductive roll provided at a location where the transfer paper 6 contacts the photoreceptor 1;
The transfer paper 6 is brought into close contact with the photoreceptor IK and at the same time receives an electric field to transfer the toner image thereon. 16 is a transfer paper peeling means provided at the rear end portion of the belt 11, and 17 is a belt cleaning means.

The electrostatic transfer paper 6 fed from the paper feed section 5 is attracted to the belt 11 by the electrostatic attraction charging means 12 and conveyed, and then transferred to the conductive roll 15 at the point where it comes into contact with the photoreceptor 1).
When the toner image is brought into close contact with the photoreceptor 1 and simultaneously subjected to an electric field, the toner image is transferred, and is further conveyed and peeled off from the belt 11 (by the transfer paper peeling means 16) and sent to the fixing section g.

In the above-mentioned apparatus, the belt 11 with a volume resistivity IQ"Ja of 51 is used, and the moving speed of the photoreceptor 1 is 270Q/s.
ec, applied voltage of the conductive roll 152. Table 1 below shows the occurrence of hollow characters depending on the moving speed V of the belt 11 when OKV is 9.

Table-1 ν: Belt movement speed - Transfer paper movement speed vP/R: Photoreceptor movement speed - 270Q/5eCO: No hollow character generated 11
9. No misalignment of the transfer paper 6 occurs.

The reason for the above results is not clear, but if the speeds of the transfer paper 6 and the photoconductor 1 are different, the toner may be affected in the moving direction between the transfer paper 6 and the photoconductor 1 during transfer. It is presumed that this is due to the fact that, due to the applied force,) the rollers of the knur are caused to eL) and a shearing force is generated on the knur layer.

Although the exact boundary line is not clear, from Table 1 above,
It can be seen that at least in order to suppress the occurrence of hollow characters, it is important that the speeds of the transfer paper 6 and the photoreceptor 1, which is a toner support, are different.

However, if the speed difference "B-vP/R" between the two is too large, the finally obtained copy image will be reduced or enlarged in the rotational direction of the photoreceptor 1 with respect to the original image fcD.

Disturbances occur in the copied image.

Therefore, within the range where these problems do not occur, the speed difference is 'B-'.
It is necessary to set P/R, but if the original f1 is set using the original reading device? When reading digitally, write on the dielectric material on the photoreceptor.In copy machines and printers, the above problems occur by correcting the reading speed and writing speed in the direction of reduction or enlargement. can be resolved.

Next, to explain the experimental results, we conducted a test in which multiple color toners were sequentially transferred onto transfer paper 6, which is similar to plain paper, using an in-house copying machine (Fuji Xerox FX6500) and developer for the same copying machine. .

The toner image of the first color is transferred to the perforated transfer paper 6 on which development is to be performed, and the toner image developed with the second color toner without fixing is transferred onto the transfer paper 6 on which the first color toner has been transferred. After transferring, all the above operations were repeated 90 times to transfer the third color toner.

tcThe moving speed 'P/R of the photoreceptor 1 at this time is BOw/
sec, and the moving speed vB of the belt 11 is g.

u/5eC1F3111J/s6C 90 As a result, if the moving speed vB of Bell II is 80 seconds, a hollow character will occur in the area where the toner images of the second and third colors overlap, and compared to 9. Therefore, when the moving speed V of the belt 11 is 8I/sec, it is assumed that no hollow characters occur at all.

From the above, by providing an appropriate difference between the moving speed 'P/R of the photoreceptor 1 and the moving speed υ of the belt 11,
It has become clear that the occurrence of hollow characters can be prevented.

In the above embodiment, by changing the speed ν3 of the belt 11, it is possible to reduce the speed difference in the moving speed 'p/i' of the photoreceptor 1, but the moving speeds of the photoreceptor 1 and the transfer paper 6 are different. It is not limited to the above embodiment as long as it can be set as follows.

For example, in the case where the transfer paper 6 is gripped and conveyed by a gripper, the moving speed of the gripper can be changed. Just make it different from the speed.

Effects of the Invention As described above in detail, the present invention has been described in detail above, and the moving speed of the photoreceptor,
The movement speed of the transfer paper, which is formed on the surface of the photoreceptor and onto which the toner image is transferred, varies, and the occurrence of so-called hollow characters, where a portion of the copied image is hollow, can be reliably prevented. It becomes like this.

Since it is only necessary to change the moving speed of the photoreceptor and the moving speed of the transfer paper, it can be easily implemented in existing copying machines and the like.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an overall configuration diagram, Fig. 2 is an enlarged side view of main parts, and Figs. 3A and 3B are explanatory diagrams showing the hollow character generation situation. It is. 1 is a photoreceptor, 6 is a transfer paper, and 7 is a transfer section.

Claims (1)

[Claims] In a device in which the toner image formed on the surface of the toner image support 1 through the latent image forming step and the development step is transferred to the transfer paper 6 in the transfer section 7, the moving speed υ of the toner image support 1 is
A transfer device characterized in that the toner image on the toner image support member 1 is transferred onto the transfer paper 6 by changing _P_/_R and the moving speed υ_B of the transfer paper 6.