| 摘要 |
PURPOSE:To use a device for cleaning and for developing combinedly by providing plural developing rolls and the reducing quantity of toner sticking onto the 1st developing roll in the introducing side of a member to be developed so as to be less than the quantity of the toner sticking onto any other rolls. CONSTITUTION:A remaining toner image on a printing master 10 in an electrostatic printing device is charged in the same polarity as an electrostatic image of said printing master by subjecting to the treatment with a transfer corotron and the charging treatment in the second turn, thence the sticking force of the toner is weakened. On the development in the 2nd turn, by reducing content of the toner in developing agent carrieod on the 1st developing roll 15 as compared with that of a roll 16, the remaining toner of which its sticking force is weakened is scraped off by the roll 15 and at the same time, a little quantity of the new toner sticks onto the roll 15, then developing in the regular photographic density is accomplished. The reduction of the content of toner is performed with a regulating member 18 and a toner pickup roll 19 which is applied with bias voltage. |
