Abstract: A cleaning blade includes a polyurethane member that constitutes at least a contact portion that comes in contact with a member to be cleaned. The polyurethane member contains a polyurethane containing a hard segment component and a soft segment component. The hard segment component has a domain particle size of about 45 nm or more and about 100 nm or less.

Abstract: A cleaning blade includes a polyurethane member that constitutes at least a contact portion that comes in contact with a member to be cleaned. The polyurethane member contains a polyurethane containing a hard segment component and a soft segment component. The hard segment component has a domain particle size of about 45 nm or more and about 100 nm or less.

Abstract: Disclosed is a cleaning blade of which a contact portion brought into contact with at least a member to be cleaned is formed of a polyurethane member that includes a polyurethane material containing a hard segment and a soft segment and has a ratio of an area occupied by a hard segment aggregate having a diameter of 0.3 ?m to 0.7 ?m in a cross section being in a range of 2% to 10%.

Abstract: Disclosed is a cleaning blade of which a contact portion brought into contact with at least a member to be cleaned is formed of a polyurethane member that includes a polyurethane material containing a hard segment and a soft segment and has a ratio of an area occupied by a hard segment aggregate having a diameter of 0.3 ?m to 0.7 ?m in a cross section being in a range of 2% to 10%.

Abstract: An image forming apparatus includes a charging roller including elastic and surface layers and a photoconductor drum. Initially, the surface layer has a surface roughness Rz of 3-6 ?m, and the layers have an impedance ratio of 0.81 or less in absolute value at a frequency of 800-3000 Hz. After a predetermined time, the surface roughness Rz is reduced by a decrement ?Rz of 0.1-4 ?m. The drum has a film thickness D initially ranging from 20-40 ?m and reduced by a decrement ?D of 5-25 ?m after the predetermined time. Herein, 0.005??Rz/?D?0.8 holds. The impedance ratio is represented as ZE/(ZE+ZS) wherein ZE and ZS represent the respective impedances of the elastic layer and the surface layer, and 100k A4-size recording media recorded with images with an area coverage of 7% are printed in the predetermined time.

Abstract: An image forming apparatus includes a charging roller including elastic and surface layers and a photoconductor drum. Initially, the surface layer has a surface roughness Rz of 3-6 ?m, and the layers have an impedance ratio of 0.81 or less in absolute value at a frequency of 800-3000 Hz. After a predetermined time, the surface roughness Rz is reduced by a decrement ?Rz of 0.1-4 ?m. The drum has a film thickness D initially ranging from 20-40 ?m and reduced by a decrement ?D of 5-25 ?m after the predetermined time. Herein, 0.005??Rz/?D?0.8 holds. The impedance ratio is represented as ZE/(ZE+ZS) wherein ZE and ZS represent the respective impedances of the elastic layer and the surface layer, and 100 k A4-size recording media recorded with images with an area coverage of 7% are printed in the predetermined time.