| 摘要 |
PURPOSE:To facilitate the adjustment of an output voltage and to make it possible to set stabilized, highly reliable density by connecting a driving coil which is connected to an oscillation source and a differential output terminal with a variable capacitance element. CONSTITUTION:The oscillated output from an oscillator 1 is applied to a driving coil 2. A reference coil 3 and a detecting coil 4 of a differential transformer are selected so that the output of the driving coil 2 becomes the differential value. The output from a differential output terminal 15 is inputted into a signal processing circuit 8. The applied voltage on the coil 2 is inputted into the other terminal of the circuit 8. The coil 2 is connected to the output terminal 15 through a capacitor 5 and a variable capacitance element 10. The oscillated output from the oscillator 1 is outputted to the coils 3 and 4 which are coupled with the coil 2. The differential output between the coils 3 and 4 is detected, and the concn. of toner is detected. The change in concn. causes the change in output of the coil 4. The differential output depending on the difference in outputs is generated between the coils 4 and 3. The phases of the output is controlled with the element 10. |
