Developing unit and image forming apparatus
View Patent ↗A developing unit includes a plurality of developing rolls over which a developer is conveyed and supplied onto an image carrier which is rotatably supported; and at least one pair of the developing rolls being adjacent to each other. In the pair of the developing rolls, one developing roll rotates in a direction opposite to a rotary direction of the image carrier, and the other developing roll rotates in the same direction of the rotary direction of the image carrier. A regulation member is interposed between the pair of the developing rolls. The regulation member regulates a conveyed amount of the developer. The regulation member is disposed to be opposed to a magnet which is provided within the two adjacent developing rolls. A polarity of the magnet in the pair of developing rolls opposed to each other is different from each other.
1. A developing unit comprising:
a plurality of developing rolls over which a developer is conveyed and supplied onto an image carrier which is rotatably supported; and
at least one pair of the developing rolls being adjacent to a developing roll which rotates in a direction opposite to a rotary direction of the image carrier and in the same direction of the rotary direction of the image carrier, the pair of the developing rolls having a regulation member being interposed between the pair of the developing rolls, the regulation member regulating a conveyed amount of the developer, the regulation member being disposed to be opposed to a magnet which is provided within two adjacent developing rolls, wherein a polarity of the magnet in the pair of developing rolls is opposed to each other are different from each other,
wherein a magnetic material is provided in a part of the regulation member disposed opposed to the magnet in the pair of developing rolls.
2. The developing unit according to claim 1 , wherein the magnetic material is provided in the regulation member is interposed between non-magnetic materials.
3. An image forming apparatus comprising:
an image carrier;
a charging unit charging a surface of the image carrier;
an exposing unit exposing the charged surface of the image carrier to light according to an image data,
a transferring unit transferring the toner image to paper,
a developing unit forming a toner image on the surface of the image carrier thus exposed,
the developing unit having a plurality of developing rolls over which a developer is conveyed and supplied onto an image carrier which is rotatably supported; and
at least one pair of the developing rolls being adjacent to a developing roll which rotates in a direction opposite to a rotary direction of the image carrier and in the same direction of the rotary direction of the image carrier, the pair of the developing rolls having a regulation member being interposed between the pair of the developing rolls, the regulation member regulating a conveyed amount of the developer, the regulation member being disposed to be opposed to a magnet which is provided within two adjacent developing rolls, wherein a polarity of the magnet in the pair of developing rolls is opposed to each other are different from each other,
wherein a magnetic material is provided in a part of the regulation member disposed opposed to the magnet in the pair of developing rolls.
4. The image forming apparatus according to claim 3 , wherein the magnetic material provided in the regulation member is interposed between non-magnetic materials.
5. The image forming apparatus according to claim 3 , wherein the process rate is 300 mm/s or more.
6. The image forming apparatus according to claim 4 , wherein the process rate is 300 mm/s or more.