|
(Portions from: Zaki (zg@ix.netcom.com).)
In general the principle of electrostatic laser
printing is as follows:
1. Charging a photoconductive selenium (or other)
coated drum.
2.Discharging the drum with the laser steering
engine in accordance with the input image rasterized pattern. (the
laser is modulated to generate a predefined pixel pattern on the
face of the drum - the focal plane).
3. The rotating drum attracts toner to the charged
pattern (latent image) generated by the laser.
4. The toner is transfered from the drum to the
moving papaer to generate a full image.
5. The paper carrying the toner moves through
the heater to fuse the toner to a fine non-erasable image.
The laser steering engine is combined of the following
components:
- Infra-red diode laser, 3 to 4 mW in basic units, up to 30 mW
or more for high performance printers.
- Beam expander to form the required size of the collimated input
beam which generates the beam spot size in the focal plan.
- Cylindrical lens to reshape the laser elliptical beam to a round
one.
- Spinning polygonal mirror to deflect the laser over the focal
plan.
- F-Theta lens to flatten the inherent circular plan of a rotating
mirror. This lens is a very special lens which only few in the
optical community know how to design and fabricate. The one that
you own is particularly special because it is a Sectioned F-Theta
lens which are typicaly more expensive (most of them are spherical).
If you need to scan or to print in high resolution 500 dpi or
higher, you end up using a glass F-Theta lens.
Back to Printer and Photocopier Technology
Save money on printer stuff now
Search below for great deals on all of your printing needs, including
printer cartridges, toner cartridges, ink refill kits, cleaning
cartridges, printer paper, and much more.
|
