Canon Kabushiki Kaisha

Shoko Funaki

Takahiro Kawamoto

Kazunari Hagiwara

Taichi Sato

Takashi Hiramatsu

Yasukazu Ikami

Shunsuke Mizukoshi

An image forming apparatus includes a rotatable photosensitive member; a charging portion, an exposure portion, a developing member, a transfer unit, a contact and separation portion, a charging voltage applying portion, a detecting portion, and a controller. The controller is capable of executing an operation in an image forming mode and an operation in a detecting mode. The controller carries out control so that a charging current flowing through a charging portion during charging of the photosensitive member in the operation in the detecting mode is lower than a charging current flowing through the charging portion during charging of the photosensitive member in the operation in the image forming mode.

Image forming apparatus

A developer used in a developing apparatus equipped with a metal blade includes a toner base particle and external additives, the external additives including a silica particle with a particle diameter of 5 nm or more and 25 nm or less and an inorganic spacer particle with a particle diameter of 50 nm or more and 150 nm or less, and an area occupancy of the silica particle on a surface of the toner base particle is 40% or more.

Developing apparatus, process cartridge, and image forming apparatus

A developing device includes a frame, a cylindrical developer carrying member rotatably supported by the frame and configured to carry a developer containing toner particles, and a regulating member fixed to the frame at one end thereof and including a contact portion which contacts the developer carrying member at the other end of the regulating member and which forms a contact nip between the regulating member and the developer carrying member. When a position of the contact portion where a maximum of a pressure distribution of the contact portion to the developer carrying member with respect to a rotational direction of the developer carrying member is indicated is a reference position, the contact portion includes a first surface portion positioned upstream of the reference position and a second surface portion positioned downstream of the reference position with respect to the rotational direction.

Developing device, regulating member, process cartridge, and image forming apparatus

A developing device includes a regulating member fixed to a frame at one end thereof and including a contact portion which contacts a developer carrying member. The contact portion includes a first region positioned upstream of a reference position and a second region positioned downstream of the reference position in a rotational direction of the developer carrying member. A length of the second region is longer than a length of the first region in a position corresponding to a contact nip with respect to a direction from a fixed end of the regulating member toward the other end as a free end of the regulating member, and the contact portion has a surface roughness smaller in the first region than in the second region, with the surface roughness in the second region being 20% or less of an average particle size of toner particles contained in a developer.

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Kanagawa, Japan

Shoko Funaki