Toner conveyance device and image forming apparatus incorporating same

An image forming apparatus comprising;

• an image carrier to carry a latent image;
• a toner supplier to contain toner;
• a development member to supply the toner supplied from the toner supplier to the latent image carried by the image carrier to form a toner image;
• a transferor to transfer the toner image from the image carrier onto an intermediate transfer member or a recording medium;
• a cleaning member to collect residual toner remaining on the image carrier after the toner image is transferred;
• a waste toner container to receive and contain the toner sent from the cleaning member;
• a first toner conveyer to convey the toner supplied from the toner supplier to the development member;
• a second toner conveyer to convey the toner collected by the cleaning member inside a housing containing the cleaning member;
• a third toner conveyer to convey the toner sent from the cleaning member to the development member;
• a fourth toner conveyer to convey the toner sent from the cleaning member to the waste toner container;
• and
• a toner conveyance device provided in at least one of the first toner conveyer, the second toner conveyer, the third toner conveyer, and the fourth toner conveyer,
• the toner conveyance device comprising:
• a conveyance path formation member that defines a conveyance path through which to convey toner;
• a conveyance member disposed within the conveyance path defined by the conveyance path formation member to rotate and convey the toner through the conveyance path in a toner conveyance direction corresponding to an axial direction of the conveyance member, the conveyance member comprising a helical blade having a helical outer circumferential surface;
• and
• a first agitator comprising a cantilevered, comb-toothed plate member of flexible material having a fixed end and a free end, the free end contacting the helical outer circumferential surface of the helical blade of the conveyance member and swinging in coordination with rotation of the conveyance member to agitate the toner as the toner is conveyed through the conveyance path,
• the first agitator further comprising:
• a body that bends in a bending direction substantially perpendicular to the axial direction of the conveyance member;
• and
• a protrusion protruding from the body in a protrusion direction opposite the bending direction of the body,
• the protrusion comprising:
• a basal portion continuous with and adjacent and connected to the body, the basal portion having a first width greater than a helical pitch of the helical blade of the conveyance member in the axial direction of the conveyance member;
• a convex portion protruding from the basal portion and having a second width smaller than the helical pitch of the helical blade of the conveyance member in the axial direction of the conveyance member;
• and
• a protrusion front edge surface provided on a front edge of the protrusion to contact the helical outer circumferential surface of the helical blade of the conveyance member,
• a distance between the protrusion front edge surface of the protrusion and the body changing within a predetermined range in the toner conveyance direction along the protrusion front edge surface of the protrusion.