Image Forming Apparatus

An image forming apparatus comprising:

• a developer-carrying body having a developer-carrying surface formed in parallel with a predetermined main scanning direction and configured to carry a developer thereon, and configured such that the developer-carrying surface is allowed move along a sub-scanning direction orthogonal to the main scanning direction;
• and
• a developer feed device disposed to face the developer-carrying body and configured to feed the developer in a charged state to the developer-carrying surface;
• wherein the developer feed device comprises:
• a plurality of transport electrodes configured to have their longitudinal direction intersecting with the sub-scanning direction and arrayed in a predetermined developer transport direction along the sub-scanning direction;
• an electricity supply wiring section connected to root portions of the transport electrodes, the root portions being one end portions of the transport electrodes with respect to the longitudinal direction;
• a developer transport body having a developer transport surface parallel to the main scanning direction, configured such that the transport electrodes and the electricity supply wiring section are provided along the developer transport surface and such that the developer transport surface faces the developer-carrying body, and configured to transport the developer along the developer transport direction by traveling-wave electric fields which are generated on the developer transport surface through application of predetermined transport voltages to the plurality of transport electrodes;
• a pair of developer transport guide members provided on the developer transport surface at opposite end portions, with respect to a width direction perpendicular to the developer transport direction, of the developer transport body, and configured to define an areal range within which the developer is transported on the developer transport surface along the developer transport direction;
• and
• a developer containing casing which is a box-like member configured to cover the developer transport body and the developer transport guide members and to contain the developer therein and which has an opening portion formed at a position where the developer-carrying body and the developer transport surface face each other,
• wherein the developer transport guide members are configured and disposed so as to be able to restrain outward leakage of the developer beyond the developer transport guide members with respect to the width direction by means of projecting toward a surface of the developer containing casing in which the opening portion is formed, at positions located inwardly, with respect to the width direction, of the root portions and distal end portions of the transport electrodes, the distal end portions being end portions of the transport electrodes opposite the root portions,
• wherein the developer transport guide members are configured to be able to restrain deposition of the developer on their top surfaces opposite their surfaces which face the developer transport surface, and
• wherein the developer transport guide members are configured such that their top surfaces opposite their surfaces which face the developer transport surface touch the developer containing casing.

An image forming apparatus comprising:

• a developer-carrying body having a developer-carrying surface formed in parallel with a predetermined main scanning direction and configured to carry a developer thereon, and configured such that the developer-carrying surface is allowed move along a sub-scanning direction orthogonal to the main scanning direction and
• a developer feed device disposed to face the developer-carrying body and configured to feed the developer in a charged state to the developer-carrying surface;
• wherein the developer feed device comprises:
• a plurality of transport electrodes configured to have their longitudinal direction intersecting with the sub-scanning direction and arrayed in a predetermined developer transport direction along the sub-scanning direction;
• a developer transport body having a developer transport surface parallel to the main scanning direction, configured such that the transport electrodes are provided along the developer transport surface and such that the developer transport surface faces the developer-carrying body, and configured to transport the developer along the developer transport direction by traveling-wave electric fields which are generated on the developer transport surface through application of predetermined transport voltages to the plurality of transport electrodes;
• a pair of first developer transport guide members provided on the developer transport surface at opposite end portions, with respect to a width direction perpendicular to the developer transport direction, of the developer transport body, and upstream, with respect to the developer transport direction, of a developing position where the developer-carrying body and the developer transport body face in the closest proximity to each other;
• and
• a pair of second developer transport guide members provided on the developer transport surface at opposite end portions, with respect to the width direction, of the developer transport body, and downstream of the developing position with respect to the developer transport direction,
• wherein the first and second developer transport guide members are configured and disposed to define an areal range on the developer transport surface within which the developer is transported along the developer transport direction, by means of restraining outward leakage of the developer beyond the first and second developer transport guide members with respect to the width direction;
• and
• the first and second developer transport guide members are configured and disposed such that a distance between the paired second developer transport guide members along the main scanning direction is greater than a distance between the paired first developer transport guide members along the main scanning direction.

An image forming apparatus comprising:

• a developer-carrying body having a developer-carrying surface formed in parallel with a predetermined main scanning direction and configured to carry a developer thereon, and configured such that the developer-carrying surface is allowed to move along a sub-scanning direction orthogonal to the main scanning direction;
• and
• a developer feed device disposed to face the developer-carrying body and configured to feed a developer in a charged state to the developer-carrying surface;
• wherein the developer feed device comprises:
• a plurality of transport electrodes configured to have their longitudinal direction intersecting with the sub-scanning direction and arrayed in a predetermined developer transport direction along the sub-scanning direction;
• a developer transport body having a developer transport surface parallel to the main scanning direction, configured such that the transport electrodes are provided along the developer transport surface and such that the developer transport surface faces the developer-carrying body, and configured to transport the developer along the developer transport direction by traveling-wave electric fields which are generated on the developer transport surface through application of predetermined transport voltages to the plurality of transport electrodes;
• and
• a spacer member provided in such a manner as to intervene between the developer-carrying body and the developer transport body, and configured to determine the distance between the developer-carrying surface and the developer transport surface at the developing position,
• wherein the spacer member is disposed to face portions of the developer-carrying body which are located outwardly of the developer-carrying surface with respect to the main scanning direction.