JPH04174480A - Corona transfer device - Google Patents

Abstract

PURPOSE:To prevent receiving effects of discharge in a non-printing zone of a photosensitive body, and obtain a good printing constantly by using a wire material of a discharge wire connected with a non-conductive wire material in a corona transfer device, and applying a mechanism to adjust a discharge width by rotation of a wire support roller. CONSTITUTION:For a photosensitive drum 6, a zone where a recording paper 7 is not put to a corona transfer device 8 is a non-printing zone, and a zone having the recording paper between them is a printing zone. A discharge wire 1 is put to face the printing zone in the photosensitive material by rotation of a wire support roller 4 and an electrode roller 5, and electric charges are applied from the electrode roller 5 to transfer a toner image. Because a non- conductive wire material 2 is facing the non-printing zone of the photosensitive material, effects of a discharge are not given.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a corona transfer device used for electrostatic transfer.

[Conventional technology]

In the conventional corona transfer device used for electrostatic transfer of dry toner, the discharge width does not have an adjustment function, and the discharge width is fixed so that the maximum print width of the image forming device can be transferred. It was customary.

[Problem to be solved by the invention]

In the conventional corona transfer device described above, the discharge width is constant, so when printing on recording paper narrower than the discharge width, the photoconductor and corona are Since a recording paper is interposed between the photoreceptor and the transfer device, it is not easily affected by corona discharge, and in the non-printing area where a toner image is not formed on the photoreceptor, the photoreceptor is transferred to the photoreceptor by the corona transfer device without using the recording paper. Directly affected by discharge.

Therefore, when printing continues for a long time, the degree of deterioration of the photoreceptor differs between the print area and the non-print area on the photoreceptor, resulting in a difference in characteristics such as chargeability and sensitivity. If printing is performed on wide recording paper under such conditions, there is a drawback that differences in the characteristics of the photoreceptors appear as density unevenness and fog.

[Means to solve the problem]

The corona transfer device of the present invention is a corona transfer device used for electrostatic transfer, in which a part of the discharge wire is coated with a non-conductive property or a wire in which a discharge wire and a non-conductive wire are connected. The discharge wire is characterized in that at least one of the plurality of rollers supporting the wire is an electrode that supplies a high voltage to the discharge wire.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1 and 2 are diagrams showing embodiments of the present invention. In the figure, 1 is a discharge wire, 2 is a non-conductive wire or a portion of the discharge wire coated with a non-conductive substance, 3 is a shield, 4 is a wire support roller, and 5 is an electrode roller.

FIG. 3 is a diagram showing an example of the use of the corona transfer device 8 shown in FIGS. 1 and 2, where 6 is a photosensitive drum and 7 is a recording sheet.

In the photosensitive drum 6, an area where the recording paper 7 is not interposed between it and the corona transfer device 8 is a non-printing area, and an area where the recording paper 7 is interposed is a printing area.

Due to the rotation of the wire support roller 4 and the electrode roller S, the discharge wire 1 faces the printing area on the photoreceptor, and charges are injected from the electrode roller 5 to transfer the toner image. Also,
At this time, since the non-printing area on the photoreceptor is opposed to the non-conductive wire 2, it is not affected by the discharge.

〔Effect of the invention〕

As explained above, the present invention uses a wire in which a discharge wire and a non-conductive wire are connected in the corona transfer device, and has the function of adjusting the discharge width by rotating the wire support roller. Since the printing area is not affected by discharge, it has the effect of always providing good printing.

[Brief explanation of drawings]

1 and 2 are sectional views of the corona transfer device of the present invention, and FIG. 3 is a diagram showing an example of use of the corona transfer device shown in FIGS. 1 and 2. 1... Discharge wire, 2... Non-conductive wire, 3...
Shield, 4... Wire support roller, 5... Electrode roller, e... Photosensitive drum, 7... Paper, 8...
...Corona transfer device. ,

Claims (1)

[Claims] A corona transfer device used for electrostatic transfer has a wire in which a part of the discharge wire is coated with a non-conductive property, or a wire in which the discharge wire and the non-conductive wire are connected, and supports the wire. A corona transfer device characterized in that at least one of the plurality of rollers is an electrode that supplies high voltage to a discharge wire.