Developing device including development container, developer carrier, and restricting blade, and image forming apparatus including the same

A developing device comprising:

• a development container having an opening and internally containing developer including toner;
• a developer carrier which is rotatably supported by he development container and has a development area where part of an outer circumferential surface carrying the developer is exposed from the opening in opposition to an image carrier, and which feeds the toner to the image carrier in the development area;
• and
• a restricting blade which is placed on an upstream side of the development area in a rotational direction of the developer carrier and which restricts layer thickness of the developer carried by the developer carrier, wherein
• the development container includes:
• a pair of side frames fitted at both end portions of the development container in a rotation-axial direction of the developer carrier to support the developer carrier;
• and
• a pair of side wall portions which are located inward of the pair of side frames in the rotation-axial direction which face each other in the rotation-axial direction with the restricting blade interposed therebetween, the pair of side wall portions having seal member insertion holes formed therein, one at each of positions respectively facing end edges of the restricting blade with respect to the rotation-axial direction, the seal member insertion holes penetrating the side wall portions from one side to another side thereof with respect to the rotation-axial direction, and
• the developing device further includes a blade-side side seal which is inserted in the seal member insertion hole to block a gap between the restricting blade and the side wall portion.