Panasonic KX-FL612CX Service Manual page 199

8.1.5. DEVELOPING AND TRANSCRIPTION
The developing is the stage that the OPC drum with an invisible image is changed to visible by the toner. The developer consists
of mixing paddle, toner supply roller, developing roller, developing blade and OPC drum. The bias voltage is added to the
developing roller (DC -200V) and toner supply roller (DC -200V). Firstly the toner is mixed up in the mixing paddle and minus-
charged by triboelectricity, then led to the toner supply roller. Secondly the potential difference causes to send the toner to the
developing roller from the toner supply roller. The supplied toner to the developing roller is kept to a certain layer thickness by the
developing blade and also it is charged by triboelectricity. Consequently the toner is transferred to the surface of the exposed OPC
drum by the potential difference between the developing roller and OPC drum´s surface.
The transfer is the stage that the created image on the OPC drum is transferred to the paper. When the transfer roller is plus-
charged with the image, the minus-charged toner particles are gathered on the surface of the drum and transferred to the paper.
The values of developing bias and supply bias are different from the ones described in the Service Manual for FL501.
The biases output from the unit of FL501,FLM551 and FLB751(FLB750) have the same voltage. However, the developing device
of FA78X(FA78A) converts the developing and supply biases inside the developing device to improve the image quality.
Developing bias
Supply bias
Developing and Transcription Part
FA77X(FA77A) developing
device
-350V
-550V
FA78X(FA78A) developing device FA84X(FA84A/FA84E) developing
-180V
-350V
199
KX-FL612CX / KX-FL612CX-S
device
-200V
-200V