(i) Technical Field
The present invention relates to a developing device and an image forming apparatus.
(ii) Related Art
The image forming apparatuses such as a printer, copier, facsimile, to which image printing methods such as an electrophotography and an electrostatic printing method are applied, are provided with developing devices each of which develops an electrostatic latent image, formed on the latent image holding member such as a rotatable photoconductor, by using a developer.
In such developing devices, there is a developing device capable of increasing development efficiency by providing plural (for example, two) developing rollers that hold a developer with a magnetic property through magnetic force and transport the developer to a development region which confronts a latent image holding member, by rotation thereof. Here, as the developing roller, for example, a developer holding carrier is used that is constituted of a transport member, which is rotatable and has a substantially cylindrical shape, and a magnet member which is fixedly disposed inside the transport member and generates magnetic force lines for holding the developer on the outer circumferential surface of the transport member through magnetic force.