JP2003015434A - Image forming device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent image quality deterioration during transfer. SOLUTION: An application device for applying a pre-transfer treatment agent (liquid) in advance before transferring a toner image onto a transfer material is provided to prevent transfer scattering. In particular, if co-paper with inkjet is widespread in the future, by adding appropriate water to the paper surface immediately before the toner image is transferred to the water-swellable resin for ink absorption existing on the co-paper surface, The paper surface becomes flexible and exhibits the effect of preventing transfer scattering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms an electrostatic latent image on an image bearing member such as a photoconductor in an electrophotographic apparatus or an electrostatic printer, and develops the electrostatic latent image to obtain an image. The present invention relates to an image forming apparatus that transfers and fixes toner.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, after an electrostatic latent image is formed on a photoconductor, a developer is electrostatically attached to the electrostatic latent image to form a developer image, and the developer image is transferred. Transfer to the transfer paper by the device. As this type of transfer device, an electrostatic means such as a corona transfer method or a roller transfer method is known.

The electrophotographic system has evolved from a copying machine and has a wide range of applications such as output of page printers and facsimiles. At the same time, there has been a demand for higher functionality, color and higher image quality from the analog system to the digital system. It is rising.

At present, in most electrophotographic apparatuses, the toner image on the photoconductor is transferred to the plain paper by the electric means as described above, but the image deterioration at the time of transfer is very large, and this point is caused by printing or inkjet. It is a major cause of inferior technology.

Recently, it was really shocking that the image quality was dramatically improved by changing the ink jet paper to the special paper except the electrophotographic field.

On the other hand, at present, there is no special paper specialized in the electrophotographic system and having such dramatically improved image quality.

[0007]

In the electrophotographic transfer system, image deterioration occurs in the process of finally transferring to the transfer paper, which is a bottleneck in the image quality of the electrophotographic system. The image deterioration in transfer is mainly caused by the unevenness of the paper, and the image is inevitably corresponding to the unevenness of the paper.

[0008]

In view of the above, according to the present invention, there is provided a coating device for coating the transfer pretreatment agent in advance on the portion to which the toner image is transferred before transferring the toner image onto the transfer material. Is characterized by.

Further, in the present invention, the transfer material has a surface coated with a swelling resin, and the transfer pretreatment agent is water.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows a full-color printer according to a first embodiment of the present invention. In this full-color printer, the laser is irradiated from the laser irradiation unit 4 to the photosensitive drum 1 in accordance with an image signal (not shown). The image signal may come from a computer or a color copier if a scanner is connected.

The photosensitive drum 1 as an image bearing member is uniformly charged to about -700 V by the corona charger 2 and receives laser irradiation L according to an image signal. As a result, an electrostatic latent image is formed on the photosensitive drum 1, and the latent image is developed by the developing device of the rotary developing unit 3 using toner as a developer, and a toner image is formed on the photosensitive member 1.

In the rotary developing unit 3, four developing units containing four color toners are arranged at 90 ° intervals, and the rotary developing unit rotates so as to face the photoconductor at the time of image formation of each color and develops. .

The intermediate transfer member 6 has a rubber drum having a medium resistance on the surface of a metal drum, and a transfer bias is applied to the metal drum.

In the present invention, before the full-color toner image is transferred from the intermediate transfer member to the transfer material T, the transfer pretreatment agent is applied to the transfer material T in advance at the portion where the toner image is transferred.

FIG. 2 shows a transfer pretreatment agent coating device 10.

The pre-transfer agent coating device 10 has a coating roller 11 and conveys and stirs the coating agent to supply it to the transfer material T. In this embodiment, the transfer material is Canon BJ paper CF1.
02, the coating agent was water.

As described above, the full-color toner image formed on the intermediate transfer member 6 on the transfer material T pre-transferred in this way is transferred onto the transfer paper by the bias applied to the transfer roller 7 as the secondary transfer means. The image is transferred and heat-fixed by the fixing device 8.

The transfer residual toner on the photosensitive drum 1 is cleaned by contacting 9A.

The feature of this embodiment is that the coating particles are previously coated on the transfer material T, and the multicolor toners on the intermediate transfer member 6 are collectively transferred from there.

However, the transfer from the intermediate transfer member to the transfer paper is
Image quality may be deteriorated. In this embodiment, water is applied to the water-swellable resin used as the ink-jet ink absorbing layer on the transfer material T to soften the surface layer to form a toner image on the surface of the photoconductor and the toner. By closely contacting each other, it is possible to improve the transferability and prevent toner scattering at the time of transfer, thereby enabling high image quality output.

(Second Embodiment) FIG. 3 shows a second embodiment.
In the present embodiment, in addition to the first embodiment, ON / OFF of the applicator 10 to the transfer material T is performed by the actuator 12 according to an image signal. There is no toner image on the entire surface,
If it is a part, the adhesive force between the softened transfer material T surface and the smooth toner-free surface of the photosensitive member increases, causing improper separation (jam) of the transfer material T from the photosensitive member 6 during transfer, which is unnecessary. In this embodiment, it is possible to reduce the soft portion on the surface of the transfer material T.

(Third Embodiment) FIG. 4 shows a third embodiment.
In this embodiment, an inkjet line head 10 'is used instead of the applicator 10 used in the first embodiment. As a result, in the second form example, the ON-De in the paper feeding direction only.
It is possible to accurately apply the transfer pretreatment agent to the surface of the transfer material T in accordance with the toner image range, since the manual application was performed faithfully.

In addition to the water-swellable resin-coated paper and water coating used in this embodiment, a transfer pretreatment agent applicator for selectively adjusting the surface state of the transfer paper to properly adjust the paper surface portion to the transfer process is provided. Of course things are possible.

[0024]

As described above, the present invention is constructed by disposing the coating device for coating the transfer pretreatment agent in advance on the portion to which the toner image is transferred before transferring the toner image on the transfer material. As a result, transfer scattering can be effectively prevented.

Further, in the present invention, the transfer material is coated with a swelling resin on its surface, and water is used as the transfer pretreatment agent. By applying water to the water-swellable resin used as the ink absorbing layer, the surface layer is softened, and the surface of the photoconductor is adhered to the toner image on the surface to improve transferability and transfer of the image. By preventing the toner scattering, it is possible to achieve high image quality output. In particular, when co-paper with inkjet becomes widespread in the future, the water-swellable resin for absorbing ink existing on the surface of the co-paper is made to contain an appropriate amount of water on the paper surface immediately before the toner image is transferred, The paper surface becomes flexible, and the effect of preventing transfer scattering can be exhibited.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a first form of an image forming apparatus according to the present invention.

FIG. 2 is a diagram showing a transfer pretreatment agent coating device in a first embodiment of the image forming apparatus according to the present invention.

FIG. 3 is a diagram showing a second form example of the image forming apparatus according to the present invention.

FIG. 4 is a diagram showing a third embodiment of the image forming apparatus according to the present invention.

[Explanation of symbols]

1 photosensitive drum 2 charger 3 developer 6 Intermediate transfer body 7 Secondary transfer roller 8 fixing device 10, 10 'Transfer pretreatment agent coating device T transfer material

Claims (2)

[Claims] 1. An image forming apparatus comprising: an electrostatic latent image forming unit that forms an electrostatic latent image on an image carrier; and a transfer unit that develops the electrostatic latent image and transfers a developer image to a transfer material. At
An image forming apparatus, comprising: a coating device for coating a transfer pretreatment agent in advance on a portion to which a toner image is transferred before transferring the toner image onto the transfer material. 2. The image forming apparatus according to claim 1, wherein the transfer material has a surface coated with a swelling resin, and the pretreatment agent for transfer is water.