Patent ID: 7991329

Claim:
A developer apparatus, comprising: a container which houses toner; a toner carrier roller which is provided, on a surface thereof, with a plurality of convex sections which are regularly arranged and a concave section which surrounds the convex sections, is shaped approximately like a cylinder, and rotates while carrying a toner layer of charged toner supplied from the container on the surface thereof; and a restriction member which abuts on the toner layer on the surface of the toner carrier roller to restrict a thickness of the toner layer, and restricts the toner layer carried by the convex sections within the surface of the toner carrier roller to one layer or less, wherein a distance between an upstream-side edge of the restriction member in a rotation direction of the toner carrier roller and the convex sections within the surface of the toner carrier roller is set to be smaller than double a volume average particle diameter of toner.