Ricoh FT5034 Service Manual page 46

3. Erase Lamp
The erase lamp illuminates the area of the charged drum surface that will not be
used for the copy image.
The erase lamp reduces toner consumption and the drum cleaning load.
Charge
Corona Unit
Original Lead
Edge
Left Scale
Sensor Pattern
Original Lead
Edge
Sensor
Pattern
The erase lamp consists of a line of 64 LEDs extending across the full width of the
drum.
The erase lamp performs lead edge erase and side erase.
The erase lamp unit also has two thermistors: TH-1 and TH-2.
Both of these thermistors detect the temperature around the drum.
TH-1 determines the proper rest time compensation, and TH-2 controls the
development bias voltage.
Erase Unit
Charged Area
Front Endblock
Cover
Original
Exposure Glass
Toner Image
Paper
Original Lead Edge
Charged Area
Lead Edge Erase Margin --- 3.5 ± 0.5 mm
A:
Side Margins --- 2 ± 2 mm each
B:
(For full size copies the total of both side
margins is less than 4 mm.)
L : Original Image width
O
L : Charged width on the Drum
C
E : Lead Edge Erase
L
E : Side Erase
S
Lead Edge Registration --- 0 ± 2 mm
R:
A+R:Lead Edge Blank Margin --- 3.5 ± 2.5 mm
- 45 -
[Density Detection Cycle]
Sensor Pattern