A printhead incorporates six nozzle arrays. Each nozzle can be controlled individually so that a six-color discharge action can be performed by a single printhead.

a) Nozzle arrays

A total of 2560 nozzles are arranged in a two-column staggered pattern.

In each column, 1280 nozzles are arranged in a staggered pattern at intervals of 600 dpi, forming a 2560-nozzle arranged at intervals of 1200 dpi.

b) Nozzle structure

Ink supplied from the ink tank is filtered by a mesh ink filter, and the supplied to the nozzles.

Ink is supplied from the shared ink chamber to the nozzles. When the head driving current is applied to the nozzle heater, ink boils and form bubbles so that ink

droplets are discharged from the nozzles.

2.3.2.5 Purge Unit

2.3.2.5.1 Functions of Purge Unit

To maintain high print quality, the purge unit performs maintenance of the nozzles o the printhead.

The purge unit supports a capping function, cleaning function, and ink supply function.

a) Capping function

The capping function presses the cap of the purge unit against the face plate on the nozzle section of the printhead to prevent nozzle drying and dust adhesion.

Capping is performed when printing is complete, at the start of the suction operation, and when switching to the standby state due to an error.

The capping function also establishes the ink passage between the printhead and purge unit.

b) Cleaning function

The cleaning function restores the printhead to the state where ink can be easily discharged from nozzles. This function includes the following three types of oper-

ations.

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