Printhead Mechanism - Epson Stylus PHOTO 890 Service Manual

EPSON Stylus Photo 890/1280/1290

2.1.1 Printhead Mechanism

The printhead mechanism operating principles of the Stylus Photo 890/1290 are
basically the same as for the previous EPSON ink jet printers. This printer, however,
employs a newly developed ink and improved printhead driving method to provide a
higher print quality and faster printing speed than ever. Also, an IC called CSIC that
stores ink-life data is attached to each ink cartridge. With this IC, ink life of each
cartridge can be individually monitored. Note, like for other models, a head voltage
must be written with a PC.
The printhead mechanism consists of ink cartridges and printheads. Each printhead is
composed of PZT (Piezo Electric Element), nozzle surface, ink supply needle, nozzle
selection circuit board, cartridge sensor, CSIC, and CSIC connection circuit. Figure 2-2
shows its component layout.
Ink Cartridge
Nozzle Plate
Figure 2-2. Printhead Mechanism
OPERATING PRINCIPLES
Nozzle Selector
CSIC
Circuit Board
CSIC Connection
Circuit
Ink Supply Needle
PZT
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Ink Cartridge
An ink cartridge stores ink to be supplied to the printhead.
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CSIC:
CSIC is a non-volatile memory EEPROM attached to each black and color ink
cartridge. It keeps the following information:
1) Ink remaining level
2) Number of cleanings performed
3) Number of installation of the ink cartridge
4) Accumulated installation time of the cartridge
5) Model name of the printer in use
6) Ink cartridge production information
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Printhead
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PZT
Driven by the print signal from the control circuit board, it ejects ink from the
nozzle plate.
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Nozzle plate
Ink pressured by the PZT is ejected from this plate.
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Ink supply needle
Connects the ink cartridge and printhead to run ink to the printhead.
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CSIC connection circuit
Connects the control circuit board and CSIC attached on the ink cartridge.
One end of the harness is connected to the control board together with the
printhead cable.
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Nozzle selection circuit board
This circuit, controlled by ASIC on the control circuit board, selects nozzles
to be driven for printing. On the other hand, head drive voltage is produced on
the controller circuit side.
Overview
Revision C
35