Imaging apparatus and process of forming image with electrophotographic photoreceptor having protective layer containing particulate P-type semiconductor

An imaging apparatus comprising:

• an electrophotographic photoreceptor;
• a charging unit to charge the surface of the electrophotographic photoreceptor, wherein the charging unit is disposed so as not to be in contact with the electrophotographic photoreceptor;
• an exposing unit to perform exposure of the electrophotographic photoreceptor charged by the charging unit;
• a developing unit to feed a toner having an externally added lubricant to the electrophotographic photoreceptor exposed by the exposing unit to form a toner image, wherein the lubricant contains a fatty acid metal salt;
• a transfer unit to transfer the toner image onto the electrophotographic photoreceptor;
• and
• a cleaning unit to remove the residual toner on the surface of the electrophotographic photoreceptor,
• wherein the electrophotographic photoreceptor comprises a conductive support, a photoreceptive layer, and a protective layer disposed in sequence,
• the protective layer comprises a resin containing a particulate P-type semiconductor,
• the particulate P-type semiconductor is a metal oxide nanoparticle, and
• the protective layer has a surface roughness Rz of 0.030 μm or more and 0.075 μm or less.

A process of forming an image, comprising the steps of:

• charging the surface of an electrophotographic photoreceptor with a charging unit, wherein the charging unit is disposed so as not to be in contact with the electro photographic photoreceptor;
• performing exposure of the charged electrophotographic photoreceptor;
• feeding a toner to the exposed electrophotographic photoreceptor to form a toner image;
• transferring the toner image formed on the electrophotographic photoreceptor;
• feeding a lubricant onto the surface of the electrophotographic photoreceptor, wherein the lubricant contains a fatty acid metal salt;
• and
• removing the residual toner on the surface of the electrophotographic photoreceptor,
• wherein the electrophotographic photoreceptor comprises a conductive support, a photoreceptive layer, and a protective layer disposed in sequence,
• the protective layer comprises a resin containing a particulate P-type semiconductor,
• the particulate P-type semiconductor is a metal oxide nanoparticle, and
• the protective layer has a surface roughness Rz of 0.030 μm or more and 0.075 μm or less.