JP2017223939A5 - - Google Patents

Claims (9)

A container containing a magnetic developer and having an opening for supplying the magnetic developer;
A developer carrier that is rotatably provided in the container at the opening and carries the magnetic developer;
A magnetic field generating member which is provided inside the developer carrier and generates a predetermined magnetic field;
A restricting member that abuts on the developer carrier and restricts the layer thickness of the magnetic developer carried on the developer carrier,
A seal member for sealing a gap between an end portion in the rotation axis direction of the developer carrier and an end portion in the longitudinal direction of the opening portion,
In a developing device including
An overlap portion arranged so that the developer carrying member, the regulating member, the sealing member, and the container are sequentially brought into contact with each other at the end portion in the longitudinal direction of the opening portion in a direction orthogonal to the rotation axis direction. Have
In the rotation axis direction, the magnetic field generation member includes a first region in which the magnitude of the magnetic flux density is a predetermined size, and one end connected to the first region to an outer end of the overlap portion in the rotation axis direction. And a second region including a minimum portion having the minimum size in the range.   2. The second area according to claim 1, wherein the size decreases from the side of the first area toward the side of the overlap portion to the minimum size and then increases again. Development device.   The second region decreases in size from the predetermined size to the minimum size from the first region side to the overlap part side, and then the minimum size is the longitudinal direction. The developing device according to claim 1, wherein the developing device continues to an end in the direction. The magnetic field generating member has at least one magnetic pole in the circumferential direction of the surface, the magnetic pole having a peak magnetic flux density in a central portion of the surface of the developer carrier facing the inside of the container in the rotation axis direction. it has, in the circumferential position with at least the pole, a developing device according to any one of claims 1 to 3, characterized in that it has the first region and the second region. The regulating member includes a fixed end fixed to the container, a free end opposite to the fixed end, and an abutting portion abutting the developer carrier between the fixed end and the free end. , And a length between the abutting portion and the free end has a short portion at the end portion in the rotation axis direction that is shorter than the central portion in the rotation axis direction,
The developing device according to claim 1, wherein a position of the short portion and a position of the second region in the rotation axis direction overlap with each other.   The developing device according to claim 5, wherein the regulating member has a constant length between the abutting portion and the free end in the overlapping portion.   7. The developing device according to claim 5, wherein the contact portion is formed over the entire area of the regulating member in the rotation axis direction.   The minimal portion has the contact portion and the free end so that the position of the free end changes in a direction inclined with respect to the rotation axis direction from the side of the central portion toward the overlap portion. The developing device according to any one of claims 5 to 7, characterized in that the length between the two is changed. An image carrier that carries a latent image,
A developing device according to any one of claims 1 to 8;
Equipped with
An image forming apparatus, wherein an image is formed on the recording material by transferring the developer image formed on the image carrier to a recording material by developing the latent image by the developing device.