| 摘要 |
PURPOSE:To improve detection efficiency with a simple constitution by detecting the magnetic brush quantity formed on a developing sleeve with a photoelectric unit installed in the specified position, comparing the same with a reference signal and measuring the remaining quantity of developer. CONSTITUTION:The magnetic brush of the developer formed on a developing sleeve 1 is detected with a photoelectric unit 7 which is constituted by the light emitting element and photo detector provided in such a manner that it becomes an angle of inclination theta2 of 10 deg. to 20 deg. toward the center of the sleeve 1 horizontally to 3a partition plate 3. When the detection voltage of the photoelectric unit 7 by the magnetic brush of the sleeve 1 of the position corresponding to the remaining quantity of the developer is compared with the voltage having been set according to the specified quantity of the residual developer in a hopper at a comparator, detection of whether the residual developer is below the specified quantity or not is highly efficiently accomplished with the simple constitution. Hence, controlling of replenishing, etc. of the developer may be well and surely performed. |
