JPH10123859A - Color image transfer method - Google Patents

Abstract

(57) [Problem] To provide a color image transfer method for performing a stable transfer by reducing a current supplied to a corotron transfer device, preventing occurrence of a leak, and performing stable transfer. SOLUTION: A plurality of color toners having a predetermined charging polarity are transferred onto an intermediate transfer body to form a color toner image on an intermediate transfer body 1, and the color toner image formed on the intermediate transfer body is transferred. This is a color image transfer method in which a predetermined current is applied to a corotron transfer device 3 disposed via a belt 2 to transfer the image to a recording medium, and a bias having a polarity opposite to a predetermined charge polarity is applied to the intermediate transfer body 1. And a predetermined current of 5
By setting the current to 0 μA to 200 μA, a current supplied to the corotron transfer device is reduced, thereby preventing a leak from occurring and providing a color image transfer method for performing stable transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a color toner image on an intermediate transfer member by transferring a plurality of color toners having a predetermined charging polarity onto an intermediate transfer member, and forming the toner image on the intermediate transfer member. The present invention relates to a color image transfer method for transferring a color toner image to a recording medium by applying a predetermined current to a corotron transfer device arranged via a transfer belt.

[0002]

2. Description of the Related Art Conventionally, a color image forming apparatus has been used as an output device such as a computer. In particular, recently, a demand for high image quality has been increasing. The method of transferring the image is important.

FIG. 2 is a configuration diagram showing an intermediate transfer unit using a conventional color image transfer method. In FIG. 2, reference numeral 1 denotes an intermediate transfer member, reference numeral 2 denotes a transfer belt, reference numeral 3 denotes a corotron transfer device, and reference numeral 4 denotes a power supply for supplying a current to the corotron transfer device 3, and these constitute an intermediate transfer unit.

In the intermediate transfer unit configured as described above, the intermediate transfer body 1 is grounded, and the color toner image formed on the intermediate transfer body 1 is transferred to a corotron disposed via a transfer belt 2. 400 μA to 6 for transfer device 3
By supplying a current of 00 μA from the power supply 4, the image is transferred between the transfer belt 2 and the intermediate transfer body 1 onto a recording medium such as paper.

[0005] As described above, the corotron transfer device 3 is provided with 400 μm.
The reason why a large current of A to 600 μA flows is that it is necessary to increase the adhesion of the color toner image in order to increase the transfer efficiency from the photoconductor (not shown) to the intermediate transfer body 1. Although the charge amount of the toner must be increased, the toner having a large charge amount is difficult to separate from the intermediate transfer member 1. Therefore, in order to transfer the toner from the intermediate transfer member 1 to the recording medium with high efficiency, it is necessary to supply a large current to the corotron transfer device 3.

[0006]

However, in the above-described conventional color image transfer method, the corotron transfer device
It is necessary to flow a large current of 00 μA to 600 μA, which causes leakage to the intermediate transfer body 1 due to pinholes of the transfer belt 2 and leakage to other components arranged around the corotron transfer device 3. And it is difficult to perform stable transfer to a recording medium such as paper.

In this color image transfer method, it is required to reduce the current supplied to the corotron transfer device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color image transfer method for reducing a current supplied to a corotron transfer device, preventing a leak from occurring, and performing stable transfer.

[0009]

In order to solve this problem, a color image transfer method according to the present invention transfers a plurality of color toners having a predetermined charging polarity onto an intermediate transfer member to transfer a color toner image to an intermediate transfer member. A color image transfer method for forming a color toner image formed on a transfer body and transferring the color toner image formed on the intermediate transfer body to a recording medium by flowing a predetermined current to a corotron transfer unit disposed via a transfer belt. , A bias having a polarity opposite to the predetermined charging polarity is applied to the intermediate transfer member,
The predetermined current was configured to be 50 μA to 200 μA.

[0010] Thus, a current supplied to the corotron transfer device is reduced, and a color image transfer method for preventing occurrence of leak and performing stable transfer can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a color toner image is formed on an intermediate transfer member by transferring a plurality of color toners having a predetermined charging polarity onto an intermediate transfer member. A color image transfer method for transferring a color toner image formed on an intermediate transfer member to a recording medium by passing a predetermined current to a corotron transfer unit disposed via a transfer belt, wherein the predetermined charge polarity and Applies a reverse polarity bias to the intermediate transfer member and applies a predetermined current of 50 μA to 200 μA.
The application of a bias to the intermediate transfer member has the effect of reducing the charge amount of the toner and improving the transfer efficiency. If the predetermined current is less than 50 μA, the necessary transfer efficiency cannot be obtained, and
If it is larger than μA, the transfer efficiency varies.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a configuration diagram showing an intermediate transfer unit and a developing unit using a color image transfer method according to Embodiment 1 of the present invention. In FIG. 1, an intermediate transfer member 1, a transfer belt 2, a corotron transfer device 3, a power supply 4
Are the same as those in FIG. 2, and therefore, are denoted by the same reference numerals and description thereof will be omitted. Reference numeral 5 denotes a photoreceptor, 6a to 6d denote developing units, and the photoreceptor 5 and the developing units 6a to 6d constitute a developing unit.

The operation and the like of the intermediate transfer unit and the developing unit configured as described above will be described.
The developing device 6a for the first color comes into contact with the photoconductor 5 on which the electrostatic latent image is recorded, and is visualized by toner. Next, the visualized toner on the photoconductor 5 reaches the intermediate transfer body 1 to which a bias having a polarity opposite to the charging polarity of the toner is applied, and the toner is transferred to the intermediate transfer body 1 by electrostatic attraction. Is done. At this time, the transfer belt 2 and the corotron transfer device 3 are separated from the intermediate transfer member 1 so as not to disturb the toner image on the intermediate transfer member 1. After the development by the first color developing device 6a and the transfer to the intermediate transfer member 1 are completed, the second color developing device 6b
Is started, and the toner is similarly transferred to the intermediate transfer body 1. Further, development and transfer to the intermediate transfer body 1 are performed in the same manner by the developing device 6c for the third color. First color ~
During the transfer of the third color, the transfer belt 2 and the corotron transfer device 3 are separated from the intermediate transfer member 1. And the last color (4
The toner image developed by the developing device 6d of (color) is transferred to the intermediate transfer body 1, and becomes a color toner image in which four colors are sequentially superimposed. When this color toner image reaches a point where it contacts the transfer belt 2 and the corotron transfer device 3,
Although the transfer of the fourth color toner to the intermediate transfer member 1 has not been completed, the transfer belt 2 and the corotron transfer device 3 abut on the intermediate transfer member 1, and at the same time, a bias is applied to the corotron transfer device 3. The transfer of the color toner image to the recording medium between the transfer belt 2 and the corotron transfer device 3 and the intermediate transfer body 1 is started.

Table 1 shows that the voltage applied to the intermediate transfer body 1 is +
One layer when the voltage of the corotron transfer unit 3 is set to 0 μA to 900 μA, and the layer thickness of the toner is set to 0.5 mg / cm ² or 1.0 mg / cm ² per layer. 3 shows measurement results of transfer efficiency to a recording medium in the first to third layers.

[0015]

[Table 1]

As is clear from Table 1, the corotron current value at which the transfer efficiency becomes maximum differs for each layer thickness. Therefore, considering a certain corotron current value as one factor, a corotron current range showing a good transfer efficiency by one-way arrangement was obtained.

Tables 2 to 6 show the results of one-way analysis.

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

[Table 5]

[0022]

[Table 6]

As is clear from Tables 2 to 6, the significance of the transfer efficiency depending on the corotron current value is as follows. There is no significant difference, the corotron current values 200 μA, 300 μA
A is significant, and the corotron current value is 300 μA to 900 μA.
There is no significant difference in the μA range. That is, a corotron current value of 50 μA to 200 μA and a corotron current value of 30 μA are used.
The range of 0 μA to 900 μA has the same variation in transfer efficiency.

Next, a practically effective range of the corotron current value is determined from the transfer efficiency confidence interval obtained from the average value of the transfer efficiency and the dispersion value in the table. As is clear from Table 2, when the corotron current value is in the range of 0 μA to less than 50 μA, the average value of the transfer efficiency is 85% or less, which is the transfer efficiency required for practical use, and is not practical. Next, as is clear from (Table 4), the corotron current value is 50 μA to 200 μA.
In the range of A, even if the average value of the transfer efficiency is taken into consideration and the dispersion obtained from the dispersion in the table is taken into consideration, the transfer efficiency required for practical use is 85% for all toner layer thicknesses.
As described above, good transfer can be obtained in this current range. Further, as is clear from Table 6, there is a portion where the confidence interval of the transfer efficiency is 85% or less in the range of the corotron current value of 300 μA to 900 μA. In some cases, it may be 85% or less, and a practically stable image cannot be obtained.

As described above, according to the present embodiment, a corotron current value of 50 μA to 200 μA is much smaller than a conventional corotron current value of 400 μA to 600 μA.
In this range, a high transfer efficiency can be obtained, so that the occurrence of leakage can be prevented and stable transfer can be performed. The reason that the corotron current value in this embodiment is smaller than the conventional corotron current value is that the intermediate transfer member 1
Since a bias (that is, a positive voltage) having a polarity opposite to the charge polarity of the toner is applied to the intermediate transfer member, the amount of charge of the toner decreases due to the influence of the bias before the toner is transferred to the recording medium. It is presumed that it was easier to move away from 1. Furthermore, the corotron current value is 300 μA to 90 μA.
As shown in the range of 0 μA, the reason why the transfer efficiency decreases as the corotron current value increases is that the charging polarity of the toner is reversed because the corotron current value is large, and the toner is charged on the recording medium due to the reverse polarity. It is presumed that transfer is not performed, and the transfer efficiency decreases.

[0026]

As described above, according to the color image transfer method of the present invention, a conventional corotron current value of 400 μA to 60 μA is used.
Corotron current value 50 μA, which is far less than 0 μA
Since a high transfer efficiency can be obtained at 200 μA, an advantageous effect of preventing the occurrence of a leak and performing stable transfer can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an intermediate transfer unit and a developing unit using a color image transfer method according to a first embodiment of the present invention;

FIG. 2 is a configuration diagram showing an intermediate transfer unit using a conventional color image transfer method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intermediate transfer body 2 Transfer belt 3 Corotron transfer device 4 Power supply 5 Photoconductor 6a-6d Developing device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuhiro Tsuru 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] A color toner image formed on the intermediate transfer member by transferring a plurality of color toners having a predetermined charge polarity onto the intermediate transfer member; and forming a color toner image on the intermediate transfer member. Is transferred to a recording medium by applying a predetermined current to a corotron transfer device disposed via a transfer belt, wherein a bias having a polarity opposite to the predetermined charging polarity is applied to the intermediate transfer body. A method for transferring a color image, wherein the applied predetermined current is 50 μA to 200 μA.