Printing Process - Epson Stylus COLOR 670 Service Manual

EPSON Stylus COLOR 670

2.1.2.1 Printing Process

This section explains the process in which the printheads of On-Demand
inkjet printers eject ink from each nozzle.
1. Normal State:
When no printing signal is sent from PC, or no PZT drive voltage is
applied, PZT does not change shape, therefore PZT does not squeeze
the cavity. Ink pressure inside the cavity is kept normal.
(Refer to Figure 2-3.)
2) Ejecting State:
When the print signal is output from the C301MAIN board, IC (Nozzle
Selector) located on the printhead unit latches data once by 1-byte
unit. An appropriate PZT latched by the nozzle selector is pushed into
the cavity by the common voltage applied from the main board. By
this operation, ink stored in the cavity spurts out from nozzles.
(Refer to Figure 2-3.)
Operating Principles
Ink Path
Overview
PZT Ink Cavity
Nozzle
Nozzle Plate
PZT drive voltage
Figure 2-3. Print Head
Revision A
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