Image developer using one-component developer
An image developer using a one-component developer, Including a developing roller visualizing an electrostatic latent image formed on an image bearer with a pulverized toner; and a feed roller feeding the pulverized toner to the developing roller while contacting thereto, wherein the pulverized toner includes a parent toner; a wax; and an external additive comprising an additive having a number-average particle diameter of from 20 to 60 nm and adhering to the surface of the parent toner at an adherence strength of from 50 to 70%, and wherein the following relationships (1) to (3) are satisfied: 4.70<Log 10 R<5.70 (1) 8.00<Log 10 Z<10.70 (2) −6.25*Log 10 R +37.5<Log 10 Z <−6.25*Log 10 R +45.6 (3) wherein R represents a resistivity of the developing roller and Z represents an impedance of the pulverized toner.
1. An image developer using a one-component developer, comprising:
a developing roller configured to visualize an electrostatic latent image formed on an image bearer with a pulverized toner; and
a feed roller configured to feed the pulverized toner to the developing roller while contacting thereto,
wherein the pulverized toner comprises:
a parent toner;
a wax; and
an external additive comprising an additive having a number-average particle diameter of from 20 to 60 nm and adhering to the surface of the parent toner at an adherence strength of from 50 to 70%, and
wherein the following relationships (1) to (3) are satisfied:
4.70<Log 10 R<5.70 (1)
8.00<Log 10 Z<10.70 (2)
−6.25*Log 10 R+ 37.5<Log 10 Z<− 6.25*Log 10 R+ 45.6 (3)
wherein R represents a resistivity of the developing roller and Z represents an impedance of the pulverized toner.
2. The image developer of claim 1 , wherein the parent toner comprises a resin.
3. The image developer of claim 1 , wherein the pulverized toner has a volume-average particle diameter of from 6 to 10 μm, and an average circularity of from 0.900 to 0.930.
4. The image developer of claim 1 , wherein the external additive is silica included in the pulverized toner in an amount of from 2.0 to 5.0% by weight.
5. A process cartridge, comprising:
an image bearer configured to bear an electrostatic latent image;
an image developer configured to develop the electrostatic latent image; and
at least one of a charger and a cleaner,
wherein the image developer is the image developer according to claim 1 .
6. An image forming apparatus, comprising:
a photoreceptor;
a charger configured to charge the photoreceptor to form an electrostatic latent image thereon;
an image developer configured to develop the electrostatic latent image with a developer comprising a toner to form a toner image on the photoreceptor;
a transferer configured to transfer the toner image onto a transfer sheet;
a fixer configured to fix the toner image on the transfer sheet; and
a cleaner configured to clean the photoreceptor to remove the toner remaining thereon,
wherein the image developer is the image developer according to claim 1 .
7. The image forming apparatus of claim 6 , wherein the fixer is an oilless fixer and the toner comprises the wax in an amount of from 3.0 to 7.0% by weight.