Page 183 - Graphic Design and Print Production Fundamentals

Graphic Design 171
toner onto the drum. The toner is attracted to the areas of the drum exposed by the laser, which, being
close to zero volts, is much more positive than the negatively charged toner. In this way, the latent image
is developed. As the carrier remains on the development roller, it continues to attract toner from the
hopper to maintain the optimal concentration on the magnetic brush.

Figure 6.7 Development

Transfer

A sheet of paper or substrate passes between the drum and a transfer charge roller that has a high positive
voltage applied to it (see Figure 6.8). The negatively charged toner of the developed latent image on the
drum is attracted to the more positive transfer roller and adheres to the sheet in-between. The charge
applied to the back of the sheet causes the paper to cling to the drum. A high negative voltage is applied
to a discharge plate immediately after the transfer charge roller to aid in the separation of the sheet
from the drum. The curvature of the drum along with the weight and rigidity of the sheet also aid in the
separation.