Developing unit having capability of efficiently exchanging developing powder
AssigneeSharp Kabushiki Kaisha
InventorsToyoka Aimoto, Masato Asanuma
Life of this patent
Estimating the term…
Abstract
A developing unit comprises a magnet roller, a stirring roller, a carrying screw, a toner density sensor, and a sensor level adjusting device. When feeding or exhausting the developing powder, the rollers and screw are driven at a slower or faster rotary speed than the speed given when developing an image. After the supply of the developing powder is terminated, the rotary speed of the rollers and the screw is changed to the speed given for developing an image. After a certain time is elapsed, the adjusting device serves to start the level adjustment when the sensor produces a stable output.
Claims13
A developing unit comprising:
- a developing bath for containing a developing powder;
- a stirring roller disposed in said developing bath for development;
- a screw disposed in said bath for carrying a developing powder to feed it inside of said bath;
- control means for controlling said roller and said screw such that rotary speeds of said roller and said screw in a case of feeding a new developing powder are not equivalent to those in a case of development, respectively;
- a sensor for outputting a signal representing a toner density in said developing bath;
- and
- means for disabling said roller and said screw when the signal supplied from said sensor reaches a predetermined value.
A developing unit comprising:
- a developing bath for containing a developing powder;
- a stirring roller disposed in said developing bath for development;
- a screw disposed in said bath for carrying a developing powder to feed it inside of said bath;
- a sensor for outputting a signal representing a toner density in said developing bath;
- control means for controlling said roller and said screw such that, after the feeding process of a new developing powder is completed, rotary speeds of said roller and said screw in a case of feeding a new developing powder are not equivalent to those in a case of development;
- and
- reference means for determining a reference output value of said sensor after a predetermined time passes from the time when said rotary speeds of said roller and said screw controlled by said control means are equivalent to those in the case of development.
A developing unit comprising:
- a developing bath for containing a developing powder;
- a stirring roller for developing disposed in said developing bath;
- a screw, disposed in said bath, for carrying a developing powder to feed it inside of said bath;
- and
- means for controlling said roller and said screw such that rotary speeds of said roller and said screw in a case of exhausting a waste developing powder are faster than those in a case of development, respectively.
A developing unit comprising:
- a developing bath for containing a developing powder;
- a stirring roller for development disposed in said developing bath;
- a screw, disposed in said bath, for carrying a developing powder to feed it inside of said bath;
- and
- means for controlling said roller and said screw such that rotary speeds of said roller and said screw in a case of exhausting a waste developing powder are slower than those in a case of development, respectively.
A developing unit comprising:
- a developing bath for containing a developing powder;
- a stirring roller for development;
- means for driving the stirring roller;
- a sensor for outputting a signal representing a toner density in said developing bath;
- means for feeding new developing powder to said developing bath;
- and
- means for disabling said feeding means and said driving means when the signal supplied from said sensor reaches a predetermined value.
Dependencies are inferred from the claim text.