Patent ID: 7920804

Claim:
A developing device comprising: a developer storing section storing a developer; a stirring member disposed in the developer storing section and transporting the developer while stirring the developer; a developer carrier receiving the developer from the developer storing section and carrying the developer; a developer regulating member regulating the amount of the developer received by the developer carrier from the developer storing section; and a heat-dissipating member disposed at a position in contact with the developer and capable of dissipating heat of the developer, the heat-dissipating member having a contact surface in contact with the developer, the contact surface having an arithmetic surface roughness Ra 1 that is set to be equal to or less than ⅓ of the volume average particle size of toner particles contained in the developer, the heat-dissipating member having a non-contact surface that is not in contact with the developer, the non-contact surface having an arithmetic surface roughness Ra 2 that is set to be equal to or greater than the arithmetic surface roughness Ra 1 , wherein the heat-dissipating member is a plate member having a first portion extending in the developer storing section and a second portion, different from the first portion, extending outside the developer storing section; and wherein the first portion has a surface set to have the arithmetic surface roughness Ra 1 and the second portion has a surface set to have the arithmetic surface roughness Ra 2 .