摘要:
A develop unit (4) is configured to include a developer roller (5) having a developer sleeve (5c) and a magnetic roller (5b) with a magnetic pole (13), a supply path (9) formed in parallel with an axial direction of the developer roller (5), a supply screw (8) supplying the developer to the developer roller (5), and a first bulkhead (133) forming the supply path (9). In the developer unit (4), the magnetic pole (13) is disposed so that a normal line (K) through a maximum magnetic flux density point (P) in a circumferential direction coincides with a tangent line to an upper portion of the supply screw (8) in a rotary direction, the maximum magnetic flux density point (P) being a point at which a density of a magnetic flux from the magnetic pole is maximum on an outer surface of the developer sleeve (5c).