Image-forming method, magnetic toner, and process unit

摘要

An image-forming method is provided which can provide stable image density irrespective of use environments and does not cause image defects such as fogging, tailing, or transfer voids, even when being applied to a developing sleeve with a reduced diameter. In the image-forming method, a latent image bearing member and a toner bearing member bearing a magnetic toner on its surface and having inside a unit for generating a magnetic field are placed with a predetermined interval, and an alternating field is applied between the latent image bearing member and the toner bearing member, and an electrostatic latent image borne by the latent image bearing member is developed with the magnetic toner. The toner bearing member has a specific diameter, and the magnetic toner has a specific circularity and a specific compressibility. The total energy of the toner measured with a powder flowability measuring apparatus satisfies a specific value.

主权项

1. An image-forming method comprising applying an alternating field between a latent image bearing member and a toner bearing member bearing a magnetic toner on the surface thereof and having inside a unit for generating a magnetic field, the latent image bearing member and the toner bearing member being placed with a predetermined interval therebetween, to develop an electrostatic latent image formed on the latent image bearing member with the magnetic toner,
wherein the toner bearing member has an outer diameter of 6.0 mm or more and 10.0 mm or less, the magnetic toner includes magnetic toner particles containing at least a binder resin and a magnetic powder, an inorganic fine powder as a flowability-improving agent, and fine particles having a primary particle diameter in excess of 30 nm, the magnetic toner has an average circularity of 0.950 or more and a compressibility of 30 or less obtained from the following expression (1):
Compressibility={1−(apparent density/tap density)}×100  (1); and a total energy of the toner measured with a powder flowability measuring apparatus satisfies the following expressions (2) and (3):
600≦TE10≦1,500  (2)TE10/TE100≦1.60  (3)where TE10 represents total energy (mJ) when a stirring rate is stirred is 10 mm/sec, and TE100 represents total energy (mJ) when a stirring rate is stirred is 100 mm/sec.