Patent ID: 8014707

Claim:
A developing device comprising: a developing roller which carries developing agent on a surface thereof, a casing which rotatably supports the developing roller; a thickness regulation blade which slidably contacts the developing roller to regulate a thickness of the developing agent on the developing roller; and first and second holding members which fix the thickness regulation blade on the casing, wherein the first holding member includes: a first nipping surface which contacts the thickness regulation blade; a projection formed on the first nipping surface and projecting toward the thickness regulation blade; and a first mounting section including a first fixing surface which extends in a direction different from a direction in which the first nipping surface extends, wherein the second holding member includes: a second nipping surface which opposes the first nipping surface; and a second mounting section including a second fixing surface which extends in a direction different from a direction in which the second nipping surface extends, the second fixing surface contacting the first fixing surface; wherein the thickness regulation blade includes a positioning opening and is sandwiched between the first nipping surface and the second nipping surface, wherein the first holding member and the second holding member are fixed to each other with the first mounting section and the second mounting section; wherein at least one of the first holding member and the second holding member is attached to the casing by the first mounting section or the second mounting section, and wherein the projection fits into the positioning opening of the thickness regulation blade.