Charge roller for noncontact charging across a charge gap, method for producing the same, and image-forming apparatus including the same

A charge roller comprising:

• a core;
• a resistive layer disposed on a circumferential surface of the core to charge an image-bearing member without contact;
• and
• gap members formed of tape-shaped films fixed to both ends of the charge roller by winding each of the films in a direction opposite a rotational direction of the charge roller in use and perpendicular to the axial direction thereof to form n layers (wherein n≧2) extending in the axial direction at every position in the circumferential direction of the charge roller, the gap members being pressed against a circumferential surface of an image-hearing member to define a charge gap between the image-bearing member and the charge roller, wherein
• the resistive layer includes thinner portions at both ends of the core and a thicker portion between the ends of the core;
• and
• the gap members are fixed to the thinner portions of the resistive layer.

A charge roller comprising:

• a core;
• a resistive layer disposed on a circumferential surface of the core to charge an image-bearing member without contact;
• and
• gap members formed of tape-shaped films fixed to both ends of the charge roller by winding each of the films in a direction opposite a rotational direction of the charge roller in use and perpendicular to the axial direction thereof to form n layers (wherein n≧2) extending in the axial direction at every position in the circumferential direction of the charge roller, the gap members being pressed against a circumferential surface of an image-bearing member to define a charge gap between the image-bearing member and the charge roller, wherein
• the core includes small-diameter portions at both ends thereof and a large-diameter portion between the ends thereof;
• the resistive layer is formed on circumferential surfaces of the small-diameter portions and the large-diameter portion so as to have a substantially uniform thickness;
• and
• the gap members are fixed to portions of the resistive layer which cover the small-diameter portions of the core.