Sharp SF-1120, SF-1020 service manual Development, Cgl Ctl

Low intensity in the area corre- sponding to the darker density portion of the document

CTL

CGL

Aluminum layer

Surface potential (High)

CTL

CGL

Aluminum layer

Medium intensity	HIgh intensity in
in the area corre-	the area corre-
sponding to the	sponding to the
medium density	lighter density of
portion of the	the document
document

	Main corona unit	Blank lamp
	Discharge lamp
	OPC drum
	Cleaning blade	Developer unit
		MG roller
Surface
potential	Surface
(Medium)
	potential
		Resist roller
	(Low)
	Seperation pawl
	Seperation corona unit	Transfer corona unit
	OPC drum

Step 3 (Development)

Toner is attached to the latent static-electricity images on the drum surface to change them to visible images. The two-component mag- netic brush development system charges toner positively by friction with carriers, and toner is attached to negative charges on the drum surface. The potential in the darker document projecting area (low intensity) is high (much negative charges) and attracts more toner. The potential in the lighter document projecting portion (high intensity) is low (less negative charges), and attracts less toner.

OPC drum
Aluminum layer	CGL CTL	Blank lamp
	Main corona unit
Higher surface	Discharge lamp
potential
(Much negative
charges)	Cleaning blade	Developer unit
Medium surface		MG roller
potential	MG roller
(Less negative
charges)
Lower surface		Resist roller
potential
(No negative	Seperation pawl
charges)	-200V
		Transfer corona unit
	Seperation corona unit
	High voltage unit
	bias voltage

At that time, a bias of –200V is applied to the MG roller (magnet roller), which is provided for preventing toner from being attracted by the residual voltage (about –80V to –100V) in the lighter portion after exposure.

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