Developing device adjustment method

Information

  • Patent Application
  • 20070217802
  • Publication Number
    20070217802
  • Date Filed
    March 08, 2007
    17 years ago
  • Date Published
    September 20, 2007
    17 years ago
Abstract
Provided is a method for adjusting a developing device including a magnetic roll (143) for holding a two-component developer (146) composed of a carrier and toner filled in a developing tank (142) in a brush state, and a developing roll (144) for developing an electrostatic latent image formed in an image carrier (110) by holding toner conveyed from the magnetic roll (143), having a bias voltage adjustment step for adjusting a conveyance amount of toner from the magnetic roll (143) to the developing roll (144) by an adjustment of bias voltages (Vdc3, Vdc4) applied to the magnetic roll (143) and the developing roll (144) respectively, and a mixing ratio adjustment step for adjusting a conveyance amount of the toner by an adjusting a mixing ratio of the two-component developer (146).
Description

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is an explanatory diagram of a developing device to which a developing device adjustment method according to the present invention is applied;



FIG. 2 is an explanatory diagram of a printer incorporated with the developing device to which the developing device adjustment method according to the present invention is applied;



FIG. 3 is an explanatory diagram of a toner concentration sensor for detecting a toner concentration on a transfer body;



FIG. 4 is an explanatory diagram of a toner image formed on the transfer body;



FIG. 5 is a graph showing a relationship between a conveyance bias voltage and a toner concentration value of a solid pattern toner image on the transfer body (a conveyance amount of toner to a developing roll);



FIG. 6 is a graph showing conveyance characteristics in an amount of toner conveyed to the developing roll, and;



FIG. 7 is a graph to explain a mechanism of adjusting a mixing ratio of a two-component developer to a target mixing ratio.


Claims
  • 1. A method for adjusting a developing device provided with a magnetic roll for holding a two-component developer composed of a carrier and toner filled in a developing tank in a brush state, and a developing roll for developing an electrostatic latent image formed in an image carrier by holding toner conveyed from the magnetic roll, comprising:a bias voltage adjustment step for adjusting a conveyance amount of toner from the magnetic roll to the developing roll by adjusting bias voltages applied to the magnetic roll and the developing roll respectively, anda mixing ratio adjustment step for adjusting a conveyance amount of the toner by adjusting a mixing ratio in the two-component developer.
  • 2. The method for adjusting the developing device according to claim 1, wherein:the mixing ratio adjustment step is executed if it is impossible in the bias voltage adjustment step to adjust a conveyance amount of the toner to a predetermined conveyance amount.
  • 3. The method for adjusting the developing device according to claim 2, wherein:the bias voltage adjustment step includes a first bias voltage adjustment step for adjusting a conveyance amount of the toner by an adjustment of a bias voltage applied to the magnetic roll so as to allow a concentration of a solid pattern formed in the image carrier or a solid pattern transferred to a transfer body to be a predetermined concentration at least in a state that a predetermined low bias voltage is applied to the developing roll.
  • 4. The method for adjusting the developing device according to claim 1, wherein:the bias voltage adjustment step includes a first bias voltage adjustment step for adjusting a conveyance amount of the toner by an adjustment of a bias voltage applied to the magnetic roll so as to allow a concentration of a solid pattern formed in the image carrier or a solid pattern transferred to a transfer body to be a predetermined concentration at least in a state that a predetermined low bias voltage is applied to the developing roll, andthe mixing ratio adjustment step is executed after adjusting the conveyance amount of the toner to a predetermined conveyance amount in the first bias voltage adjustment step.
  • 5. The method for adjusting the developing device according to claim 1, comprising:the bias voltage adjustment step further includinga first bias voltage adjustment step for adjusting a conveyance amount of the toner by an adjustment of a bias voltage applied to the magnetic roll so as to allow a concentration of a solid pattern formed in the image carrier or a solid pattern transferred to a transfer body to be a predetermined concentration at least in a state that a predetermined low bias voltage is applied to the developing roll, anda second bias voltage adjustment step for adjusting bias voltages applied to the magnetic roll and the developing roll respectively while maintaining a differential voltage of the bias voltages in a constant state so that a concentration of a predetermined halftone pattern formed in the image carrier or a predetermined halftone pattern transferred to a transfer body is brought into a predetermined concentration after executing the first bias voltage adjustment step,wherein:the mixing ratio adjustment step is executed after completing an adjustment by the bias voltage adjustment step.
Priority Claims (1)
Number Date Country Kind
2006-076040 Mar 2006 JP national