EPSON Stylus PHOTO 810/820/830

Revision B

2.1.2.1 Printing Process

This section explains the process which the Printheads of On-Demand inkjet printers eject ink from each nozzle.

1.Normal state :

When the printing signal is not output from the Main board (C418 Main/Main-B, C483/C484 Main), or the PZT drive voltage is not applied, the PZT does not change the shape. Therefore, the PZT does not push the ink cavity. The ink pressure inside the ink cavity is kept normal. (refer to Figure 2-4 : Normal state)

2.Ejecting state :

When the print signal is output from Main board (C418 Main/Main-B, C483/C484 Main), the nozzle selector IC located on the Printhead latches the data once by 1- byte unit. Based on the drive waveform (common voltage) generated on the Main board, the PZT selected by the nozzle selector IC pushes the top of the ink cavity. By this operation, the ink stored in the ink cavity is ejected from nozzles. (refer to Figure 2-4 : Ejecting state)

Ink path

PZT

Ink cavity

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Normal state

Nozzle

Nozzle plate

PZT drive voltage

Ejecting state

2.1.2.2 Printing Method

For printing dot system, the Stylus PHOTO 810/820 has the following two kinds of printing mode.

„Multiple shot printing

„Variable dot printing

The above two printing modes are automatically selected depending on the media and the resolution setting of the printer driver. The following explains each printing mode.

†Multiple shot printing

This printing mode is developed to improve the print quality on plain paper or transparencies in low resolution. The multiple shot printing mode uses normal dot, and the number of dot shot varies from 1 shot to maximum 3 shots depending on the print data to enable to output sharp image even in a low resolution.

†Variable dot printing

This printing mode is developed to improve the print quality on exclusive paper. This mode is basically the same as variable dot printing mode used on other products; micro dot, middle dot and large dot compose this mode. The printing dot size varies according to the print data and this mode enables to output even sharper image on exclusive paper.

Figure 2-4. Printhead printing process

Operating Principles

Overview

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