Exposure - Brother MFC-9320CW Service Manual

3.6.2

Exposure

Exposure is conducted by LED (Light Emitting Diode) arrays.
Four LED arrays for K, Y, M and C are mounted as an LED ASSY on the top cover unit of the
main unit. These four LED arrays do not emit different colors corresponding to toner colors,
and they are the same parts in terms of structure.
On the PCB in the LED array, 4,992 LEDs, which correspond to the total number of the dots of
the 600-dpi print head, are arranged in a staggered pattern. The lens array forms image on
the exposure drum using the light emitted from the LEDs. The surface potential on the
exposure drum, which is evenly charged, is lowered by exposure, and consequently image is
formed.
Memo:
- The focus adjustment of the distance between the LED ASSY and exposure drum is
made by the lower rollers at the both ends of the LED ASSY, and a fixed distance is
maintained.
- Maximum print width is 207.44 mm = 4,900 dots.
LED array
Exposure drum
* Figure of the side view
LED ASSY
LED ASSY
Roller
LED array
Fig. 2-22
* Figure of the front view
Fig. 2-23
2-25
LED array
Lens array
Roller
Exposure drum
Confidential