Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A developing device includes a frame, a cylindrical developer carrying member, and a regulating member including a contact portion. 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 region positioned upstream of the reference position and a second region positional downstream of the reference position with respect to the rotational direction. The contact portion has surface roughness smaller in the first region than in the second region. The surface roughness in the second region is 20% or less of an average particle size of toner particles contained in the developer.

Abstract: 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.