Patent attributes
A method and apparatus to clear the accumulation of toner particles from a doctor element by periodically reversing a bias field between a doctor element and a developer member. The developer member may be biased to a first electrical potential while the doctor element may be biased to a second electrical potential. The second electrical potential may be higher than the first electrical potential. The doctor element and the developer member may be biased from a single voltage supply and a voltage dividing circuit. A bias reversing circuit may cause the second electrical potential to fall, at least temporarily, below that of the first electrical potential when power from the voltage supply is removed. The bias reversing circuit may also cause the first electrical potential to fall with a longer time constant than that of the second electrical potential when power from the voltage supply is removed.