K117sm3e1
3-7
3. 1. 2. 3 Exposure
According to the printed image pattern, the LED Head throws the light (740nm) onto some part of
Drum which corresponds to the black area of printed image pattern.
As the Drum has a characteristic to lose the negative electric charges if it is exposed to the light,
this part of Drum surface loses the charges and its potential becomes about -20V. (This potential is
not constant but is variable by the environment.)
The other part of Drum surface, which was not exposed to the light from the LED Head, keeps
-630V of potential which the Image Corona has given.
An invisible electric image pattern that consists of -630V area and the -20V area is formed on the
surface of Drum as a result. (This is called “Electrostatic Latent Image”.)
(Distribution of electric potentials after the Exposure)
(see the next page)
-20V -630V
Drum
LED Head
To Next Page
Loading...
