Lexmark MS312, Service Manual, Page: 318 / 343

# Part
1 First input roller
2 Secondary input roller
3 Duplex front deliver roller
4 Duplex rear deliver roller
5 Paper exit roller
Media handling components
Main drive gearbox
The gearbox supplies all mechanical power requirements of the printer. Its motor, through several gears,
transfers power to following paths: photoconductor drum, transfer roll, fuser, paper exit, input, duplex, and MPF.
Aside from providing rotational motion to rollers and feeders, the gearbox must also ensure that the print image
is not distorted during the whole process. It must also provide easy and effective means to cut or break the
transfer of motion when taking the cartridge unit out of the machine, or when clearing jammed sheets through
its linkage system.
Autocompensator mechanism (ACM)
The fundamental function of the ACM is to pick and feed a single sheet of media and accurately deliver it to
the downstream paper path. The pick arm is counterbalanced to provide a priming force throughout the entire
range of paper levels in the tray. When media is picked, a subsequent sheet is not picked until the previous
sheet's trailing edge is detected by the trailing edge sensor. Once the trailing edge of the media is detected,
and the minimum interpage gap is satisfied, the next sheet will be picked.
4514-330
Theory of operation
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