Xerox Phaser 6128 MFP, Service Manual

Page: 87 / 606

Phaser 6128MFP Service Manual 2-33
Theory of Operation
Printer Modes
Operational Modes
The Phaser 6128 printer includes the following modes:
• Ready Mode
The printer is ready for printing.
• Printing Mode
Printing is in progress.
• Sleep Mode
The printer has entered a power saving state.
• Deep Sleep Mode
The printer has entered a power saving state.
Printer Control
Paper Size Detection
The printer has no switches for detecting paper size; only the length of the paper is
detected by the Regi Sensor as the paper is feeding. If the detected size does not
match the size sent in the print data, an error is reported to the Image Processor.
Laser Unit Light Quantity Control
Image data is sent to the Laser Unit as an electric signal (data are expressed with
high and low voltage values), and the laser diodes convert the image data from
electric signals to optical signals (data are expressed with blinking laser beams).
Variations in light quantity of laser beams or variations in the optical system (such
as lenses) or drum sensitivity cannot attain a proper electrostatic image.
Therefore, the laser beam light quantity is monitored and controlled by the laser
diodes.
The Laser Unit has four laser diodes for Yellow, Magenta, Cyan, and Black
respectively and the beam intensity is automatically adjusted for each color.