| 摘要 |
PURPOSE:To obtain an image of high picture quality stably for a long period by forming electrodes for an electric field curtain so that its cross section is in a flat plate shape at a development part facing a latent image carrier and intermediately high at conveyance parts before and behind it. CONSTITUTION:For example, when a 3-phase AC voltage is applied to electrode groups 4, 4a, and 4b, a moving electric field is produced and the toner at the reservoir part at the lower part of a container 2 is conveyed in a direction alpha. A drum 6 serves as a counter electrode to the electrodes 4 at the development part and while the toner is in reciprocal motion between the drum and electrode group 4, development is performed and the toner is consumed, so the toner is conveyed smoothly without being deposited on the electrodes 4. The electrodes 4 are flat plates, so neither edge effect nor white absence at a solid part is caused. The toner passed through the development part is conveyed to the upper part by a conveyance electrode 4b to falls from the upper end of a panel and is recovered in the container 2 and reused. The top surfaces of conveyance electrodes 4a and 4b are intermediately high, so not toner is conveyed smoothly without being deposited on the top surfaces of the electrodes, so that an image of high picture quality is obtained stably for a long period. |
