1. Field of the Invention
The present invention relates to an image forming apparatus and a method of using the same, and more particularly, to a wet-type color image forming apparatus and a method of preventing a flow pattern of an ink image using the same.
2. Description of the Related Art
As there is a need of reducing a size of a wet-type color image forming apparatus, a method of removing a developing solution supply unit or simplifying a structure of the wet-type color image forming apparatus has been suggested to reduce the size of the wet-type color image forming apparatus. As a result, ink having toner concentration of more than 12% is not diluted but is used as is without change.
In the related art, a developing process using the high-concentration ink is performed using a direct contact method in which a developing roller contacts a photosensitive body. In the direct contact method, preferably, the high-concentration ink stained in the developing roller is completely used for developing a latent electrostatic image that is formed on the photosensitive body. However, remaining ink that is not completely used for developing the latent electrostatic image but drifts away exists between the photosensitive body and the developing roller in the developing process, and the remaining ink accumulates, as shown in FIG. 1. A hold up volume 16, which is a bundle of the remaining ink, is formed between a developing roller 12 and a photosensitive body 10. The hold up volume 16 might be used to develop the latent electrostatic image with ink 14 that is newly supplied in the developing process.
However, since the ink 14 forming the hold up volume 16 is not be electrically controlled in comparison with new ink 14 having an electrical potential, the ink 14 forming the hold up volume 16 is moved to the photosensitive body 10, and then drops downward immediately. As a result, a part of the latent electrostatic image may be not developed or incompletely developed. In addition, a part of the ink 14 that is normally moved to the photosensitive body 10 from the developing roller 12 is torn off and separated from the ink 14 by a viscous force of the remaining ink 14 contained in the developing roller 12. Due to the separation of the ink 14, the part of the latent electrostatic image is not developed or incompletely developed. A metering blade 18 coats the ink 14 having a predetermined thickness on a surface of the developing roller 12.
As mentioned above, in order to avoid to the remaining ink 14 contained in the hold up volume 16 or the developing roller 12, high-concentration ink is used. However, a stripe so-called a flow pattern is formed in a developing direction when the photosensitive body 10 directly contacts the developing roller 12. Due to the flow pattern, a final resultant (image) is formed in a solid phenomenon, in which an excessive amount of the ink 14 is attached to an image portion more than a blank portion of the latent electrostatic image, in the developing direction.
The flow pattern is completely removed when the ink prepared on the surface of the developing roller is completely used for developing the latent electrostatic image in the developing process. That is, in a case where the ink prepared on the surface of the developing roller is moved to the photosensitive body, the remaining ink disappears from the surface of the developing roller, and the hold up volume is not formed between the developing roller and the photosensitive body, and thus the flow pattern does not to exist in the developed latent electrostatic image.
However, to do this, an amount of the ink prepared on the surface of the developing roller should be minimized. In a case where the amount of the ink is minimized, an optical density of the developed resultant deteriorates, and thus a final image fades.
USPTO Backgrounds
USPTO Backgrounds