Charging device, image former, and image forming apparatus that electrically charge a surface of a charging target member
A charging device includes a charging member and a cleaning member. The charging member electrically charges a surface of a charging target member and is rotatable while being in contact with the surface of the charging target member. The cleaning member is in contact with a surface of the charging member and removes a foreign object attached to the surface of the charging member. Surface free energy of the surface of the charging member is 5.00 dynes per centimeter or more. A dynamic friction coefficient of the surface of the charging member and a surface of the cleaning member falls within a range from 0.48 to 0.88 both inclusive. The surface free energy and the dynamic friction coefficient satisfy a relation represented by the following expression (1). E ≤−63μ+69 (1) “E” is the surface free energy in dynes per centimeter, and “μ” is the dynamic friction coefficient.
1. A charging device comprising:
a charging member that electrically charges a surface of a charging target member and is rotatable while being in contact with the surface of the charging target member; and
a cleaning member that is in contact with a surface of the charging member and removes a foreign object attached to the surface of the charging member, wherein
surface free energy of the surface of the charging member is 5.00 dynes per centimeter or more,
a dynamic friction coefficient of the surface of the charging member and a surface of the cleaning member falls within a range from 0.48 to 0.88 both inclusive, and
the surface free energy and the dynamic friction coefficient satisfy a relation represented by the following expression (1),
E≤− 63μ+69 (1)
where “E” is the surface free energy in dynes per centimeter, and “μ” is the dynamic friction coefficient.
2. The charging device according to claim 1 , wherein the surface free energy is 13.49 dynes per centimeter or less.
3. The charging device according to claim 1 , wherein the charging member includes a first surface layer having a surface that includes fluororesin.
4. The charging device according to claim 3 , wherein the first surface layer includes a mixture of epichlorohydrin rubber and acrylonitrile-butadiene rubber.
5. The charging device according to claim 1 , wherein the cleaning member includes a second surface layer having a surface that includes foamed polyurethane.
6. An image former comprising:
a developing device that includes a photosensitive member and performs a developing process with use of a toner; and
a charging device that performs a charging process on a surface of the photosensitive member, the charging device including
a charging member that electrically charges the surface of the photosensitive member and is rotatable while being in contact with the surface of the photosensitive member, and
a cleaning member that is in contact with a surface of the charging member and removes a foreign object attached to the surface of the charging member, wherein
surface free energy of the surface of the charging member is 5.00 dynes per centimeter or more,
a dynamic friction coefficient of the surface of the charging member and a surface of the cleaning member falls within a range from 0.48 to 0.88 both inclusive,
the surface free energy and the dynamic friction coefficient satisfy a relation represented by the following expression (1),
E≤− 63μ+69 (1)
where “E” is the surface free energy in dynes per centimeter, and “μ” is the dynamic friction coefficient.
7. An image forming apparatus comprising:
an image former that performs a charging process and a developing process,
a transfer section that performs a transfer process with use of a toner subjected to the developing process by the image former; and
a fixing section that performs a fixing process with use of the toner subjected to the transfer process by the transfer section,
the image former including
a developing device that includes a photosensitive member and performs a developing process with use of a toner; and
a charging device that performs a charging process on a surface of the photosensitive member, the charging device including
a charging member that electrically charges the surface of the photosensitive member and is rotatable while being in contact with the surface of the photosensitive member, and
a cleaning member that is in contact with a surface of the charging member and removes a foreign object attached to the surface of the charging member, wherein
surface free energy of the surface of the charging member is 5.00 dynes per centimeter or more,
a dynamic friction coefficient of the surface of the charging member and a surface of the cleaning member falls within a range from 0.48 to 0.88 both inclusive,
the surface free energy and the dynamic friction coefficient satisfy a relation represented by the following expression (1),
E≤− 63μ+69 (1)
where “E” is the surface free energy in dynes per centimeter, and “μ” is the dynamic friction coefficient.