Abstract: An image forming apparatus includes an image bearer, a charger, a developing device, and a transferor. The charger is disposed in contact with the image bearer to charge the image bearer. The developing device supplies toner to the image bearer to form a toner image on the image bearer. The transferor transfers the toner image on the image bearer to a recording medium or an intermediate transferor. The developing device collects transfer residual toner remaining on the image bearer after transfer of the toner image. The toner contains base particles and an external additive. The external additive has a volume average particle diameter of 5 nm or more and 50 nm or less. A content of the external additive is 1.8% by mass or less in the toner.

Abstract: A developing device includes a developer bearer facing a latent image bearer, to rotate and supply developer to the latent image bearer, and a developer regulator to regulate an amount of the developer on a surface of the developer bearer. The developer regulator is in contact with the surface of the developer bearer. In the developing device, a ratio of a ten-point mean roughness of the developer regulator to a volume average particle diameter of the developer is not greater than 3.5%. The ratio is defined as Rzjis/Dv×100, where Rzjis represents the ten-point mean roughness measured in a nip-adjacent portion of a face of the developer regulator opposing the developer bearer, and Dv represents the volume average particle diameter of the developer. The nip-adjacent portion is adjacent to and downstream a downstream end of a regulation nip in a rotation direction of the developer bearer.

Abstract: A developing device includes a toner bearer to rotate while bearing toner and a toner regulator including a bend on a free end side. The bend is disposed in contact with a surface of the toner bearer and defines a regulation nip to adjust an amount of the toner on the toner bearer. The toner regulator further includes an area having a water contact angle greater than or equal to 70 degrees. The area having the water contact angle includes, at least, a downstream end of the bend in a rotation direction of the toner bearer.

Abstract: A developing device includes a developer bearer facing a latent image bearer, to rotate and supply developer to the latent image bearer, and a developer regulator to regulate an amount of the developer on a surface of the developer bearer. The developer regulator is in contact with the surface of the developer bearer. In the developing device, a ratio of a ten-point mean roughness of the developer regulator to a volume average particle diameter of the developer is not greater than 3.5%. The ratio is defined as Rzjis/Dv×100, where Rzjis represents the ten-point mean roughness measured in a nip-adjacent portion of a face of the developer regulator opposing the developer bearer, and Dv represents the volume average particle diameter of the developer. The nip-adjacent portion is adjacent to and downstream a downstream end of a regulation nip in a rotation direction of the developer bearer.

Abstract: A developing device includes a toner bearer to rotate while bearing toner and a toner regulator including a bend on a free end side. The bend is disposed in contact with a surface of the toner bearer and defines a regulation nip to adjust an amount of the toner on the toner bearer. The toner regulator further includes an area having a water contact angle greater than or equal to 70 degrees. The area having the water contact angle includes, at least, a downstream end of the bend in a rotation direction of the toner bearer.