| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent occurrence of image failure by maintaining the appropriate range of toner layer thickness on a developing roller by a simple structure in a developing device using two-component developer. <P>SOLUTION: A magnetic brush composed of a magnetic carrier and nonmagnetic toner is formed on the periphery of a magnetic roller 25a. While the magnetic brush is slide over the developing roller, toner is transferred to the developing roller according to a potential difference between the magnetic roller and the developing roller. Thus, development is carried out by forming the thin layer of toner onto the developing roller. To carry out the development, the potential difference is changed and a density detection pattern is formed as a toner image for each of potential differences that differ from one another. Image density is obtained by detecting the density of each density detection pattern, and a set potential difference is determined according to the amount of toner forming the thin layer for each of the potential differences and image density for each of the potential differences. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
