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Service Guide ML520/521
Chapter 2 Principles of Operation
2.1.04 Print Control
The print data is transmitted as serial data from the LSI to the control circuit and the driver contained in
the printhead.
After the data is printed, the sensor analog circuit controlling each pin returns the pin stroke data to the
MPU. The MPU will make an automatic head gap adjustment. This feedback system sets the optimum
drive time for each pin in order to maintain high print quality.
In the case of envelopes, where the medium thickness varies as the printhead moves along the platen,
the strike force of the pins changes to compensate for the differences in thickness.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
