| 摘要 |
A system for controlling the concentration of developer solution, which includes a toner concentrate and a carrier, to be substantially equal to a predetermined concentration. The system, which is used in conjunction with a photocopying apparatus, comprises a source of light directed through the solution and a photosensor, on which the light source is focused, that generates an output signal proportional to the amount of light reaching it. A reference signal generator produces a reference signal substantially equal to the photosensor output signal that corresponds to the predetermined solution concentration. A comparator receives both the photosensor output and the reference signals and produces an error signal proportional to the difference between the two. The error signal is used to modulate the amount of time during which a servo mechanism is operated to add toner concentrate to the solution and thereby control solution concentration.
|
