Laser Exposure; Development; Drum Cleaning; Figure 2-6. Laser Exposure - Epson EPL-N1200 Service Manual

EPL-N1200 Service Manual Operating Principles

2.1.1.3 Laser Exposure

Laser exposure is the process of creating an invisible static electric image on the PC drum with
laser beams emitted from the optical unit. The mirror scanner motor (polygon motor) rotates the
six-sided mirror counterclockwise to produce a laser light scan. (One side of the mirror produces
one scan.) The SOS (start of scan) sensor detects the laser rays from the SOS mirror and outputs
the SOS signals to make the starting position of each line of the image uniform.

Figure 2-6. Laser Exposure

2.1.1.4 Development

Development is the process of creating a toner image on the PC drum by applying toner to the
invisible static electric image. The doctor blade spreads a thin, even coat of toner over the flexible
sleeve. When the toner passes between the doctor blade and the flexible sleeve, it becomes
negatively charged. The flexible sleeve transports toner to the surface of the PC drum and controls
the development with the developing bias voltage.
No positively charged toner is transported to the PC drum, and the doctor blade is negatively
charged to prevent the printout from having a foggy background.

Figure 2-7. Development

2.1.1.5 Drum Cleaning

After the image is transferred onto paper, any remaining toner on the PC drum is scraped off by the
cleaning blade and collected in the used toner bottle.
Rev. A 2-5