Printing Process - Epson Stylus Photo 895 Service Manual

EPSON Stylus PHOTO 895/785EPX
Nozzle Layout
Black: 48 nozzles (120 dpi)
Color: 48 nozzles x5(Cyan, Magenta, Yellow, Light cyan, Light magenta)(120dpi)
The nozzle layout when viewed from the back surface of the head is shown below.
Figure 2-3. Nozzle Layout
Operating Principles

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.
2. Ejecting State:
When the print signal is output from the C408 MAIN 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.
Ink Path
Nozzle
Figure 2-4. Printhead Printing Process
Overview
PZT
Ink Cavity
Nozzle plate
PZT drive voltage
Revision A
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