Transfer roller, image-forming apparatus, and process cartridge
View Patent ↗A transfer roller includes a conductive support, a first conductive elastic layer disposed on the conductive support, and a second conductive elastic layer disposed on the first conductive elastic layer. A common logarithm of surface resistivity of the second conductive elastic layer is higher than a common logarithm of volume resistivity of the second conductive elastic layer by about 1 or more.
1. A transfer roller comprising:
a conductive support;
a first conductive elastic layer disposed on the conductive support; and
a second conductive elastic layer disposed on the first conductive elastic layer, wherein a common logarithm of surface resistivity of the second conductive elastic layer is higher than a common logarithm of volume resistivity of the second conductive elastic layer by about 1 or more.
2. The transfer roller according to claim 1 , wherein the second conductive elastic layer comprises a tubular elastic member stretched to an elongation of about 50% to about 100% in a radial direction thereof.
3. The transfer roller according to claim 2 , wherein the second conductive elastic layer is ionically conductive.
4. The transfer roller according to claim 1 , wherein the second conductive elastic layer is ionically conductive.
5. An image-forming apparatus comprising:
an image carrier having a surface;
a charging unit that charges the surface of the image carrier;
a latent-image forming unit that forms a latent image on the charged surface of the image carrier;
a developing unit that develops the latent image formed on the surface of the image carrier with a toner to form a toner image; and
a transfer unit that transfers the toner image from the surface of the image carrier to a recording medium, the transfer unit comprising the transfer roller according to claim 1 .
6. A process cartridge attachable to and detachable from an image-forming apparatus, the process cartridge comprising:
at least one unit selected from the group consisting of an image carrier having a surface, a charging unit that charges the surface of the image carrier, a latent-image forming unit that forms a latent image on the charged surface of the image carrier, and a developing unit that develops the latent image formed on the surface of the image carrier with a toner to form a toner image; and
a transfer unit that transfers the toner image from the surface of the image carrier to a recording medium, the transfer unit comprising the transfer roller according to claim 1 .