Developing device and image forming apparatus

1. A developing device comprising:

a developer bearing body that partially faces an inside of a developer storing chamber, said developer bearing body being rotatable and bearing a developer;

a first developer carrying member disposed in said developer storing chamber together with said developer bearing body, said first developer carrying member rotating to carry said developer in an axial direction, and

a second developer carrying member disposed in said developer storing chamber together with said first developer carrying member, said second developer carrying member rotating to carry said developer in an axial direction,

wherein said first developer carrying member carries said developer from end portions of said developer storing chamber toward a center portion of said developer storing chamber, and said second developer carrying member carries said developer from said center portion toward said end portions, and

wherein an amount of said developer carried from said end portions toward said center portion of said developer storing chamber is greater than an amount of said developer carried from said center portion toward said end portions of said developer storing chamber.

2. The developing device according to claim 1 , wherein a distance between said first developer carrying member and said developer bearing body is less than a distance between said second developer carrying member and said developer bearing body.

3. The developing device according to claim 1 , wherein said first and second developer carrying members respectively have spiral portions, and

wherein an outer diameter of said spiral portion of said first developer carrying member is larger than an outer diameter of said spiral portion of said second developer carrying member.

4. The developing device according to claim 1 , wherein said first and second developer carrying members respectively have spiral portions, and

wherein a pitch of said spiral portion of said first developer carrying member is larger than a pitch of said spiral portion of said second developer carrying member.

5. The developing device according to claim 1 , wherein said first and second developer carrying members respectively have spiral portions that form grooves, and

wherein a depth of said groove of said first developer carrying member is deeper than a depth of said groove of said second developer carrying member.

6. The developing device according to claim 1 , wherein said first developer carrying member has a spiral portion, and

wherein a pitch of said spiral portion at each end portion of said first developer carrying member is larger than a pitch of said spiral portion at a center portion of said first developer carrying member.

7. The developing device according to claim 1 , further comprising a developer supply port for supplying said developer to said developer storing chamber,

wherein said developer supply port is disposed on a center portion of said developer storing chamber in an axial direction of said developer bearing body.

8. The developing device according to claim 1 , further comprising a leveling member disposed above said first and second developer carrying members for leveling said developer stored in said developer storing chamber.

9. An image forming apparatus comprising:

said developing device according to claim 1 .

10. The developing device according to claim 1 , further comprising a developer supplying member disposed below said first and second developer carrying members,

wherein said developer carried by said first and second developer carrying members is supplied to said developer bearing body via said developer supplying member.