Abstract: A developing apparatus in a transfer-type electrophotographic system having a photosensitive body, wherein the developing apparatus includes a developing roller spaced a small distance from the photosensitive body for supplying a developing solution to the photosensitive body to develop a latent image thereon and to induce a potential on the developing roller through the developing solution from the photosensitive body. A cleaning member is held against the developing roller. In one embodiment, the potential of the developing roller is limited to a level intermediate between predetermined upper and lower limits, an a developing roller is switched into an electrically floating condition except during development of an image. In another embodiment, a developing bias potential is produced responsive to the potential of the developing roller. The bias potential is then applied to the developing roller which is used as a developing electrode.

Abstract: A developing apparatus in a transfer-type electrophotographic system having a photosensitive body, wherein the developing apparatus includes a developing roller spaced a small distance from the photosensitive body for supplying a developing solution to the photosensitive body to develop a latent image thereon and to induce a potential on the developing roller through the developing solution from the photosensitive body. A cleaning member is held against the developing roller. In one embodiment, the potential of the developing roller is limited to a level intermediate between predetermined upper and lower limits, and a developing roller is switched into an electrically floating condition except during development of an image. In another embodiment, a developing bias potential is produced responsive to the potential of the developing roller. This bias potential is applied to the developing roller which is used as a developing electrode.

Abstract: A device for supplying a developing solution in a wet-type electrophotographic copying machine has a scraper pressed against a developing roller positioned in confronting relation to a latent-image carrier or photosensitive drum. The scraper and the developing roller jointly form a space of a V-shaped cross section which serves to form a pool of the developing solution. When the developing roller is rotated, the developing solution is drawn upwardly out of the solution pool and uniformly covers the circumferential surface of the developing roller whereupon it is transferred to the latent-image carrier. The apparatus provides a simple way of eliminating air bubbles from the developing solution before it is applied to the latent-image carrier and for applying the developing solution uniformly to the surface of the latent-image carrier.