Print Mechanism (Print Head) - Epson Stylus Pro 7400 Service Manual

EPSON Stylus Pro 7400/7800/9400/9800

2.2.1 Print Mechanism (Print Head)

Stylus Pro 7400/7800/9400/9800 employ a single print head which incorporates both
functions for black and color as the previous model; Stylus Pro 7600/9600.
The print head incorporates a thermistor. According to the temperature around the head
detected by the thermistor, the CPU on the Main Board controls the ink discharge
speed and the amount of ink to be discharged.
Printing method: On-demand ink-jet
Nozzle configuration:
180 nozzles x 8 rows = 1440 nozzles (See
Black: Stylus Pro 7800/9800 (8-color model): 540 nozzles
(180 nozzles for each of Black1, Black2, and Black3)
Stylus Pro 7400/9400 (4-color model): 360 nozzles
(180 nozzles for each of Black1 and Black2)
Color: Stylus Pro 7800/9800 (8-color model): 900 nozzles
(180 nozzles for each of cyan, magenta, light cyan, light
magenta and yellow)
Stylus Pro 7400/9400 (4-color model): 1080 nozzles
(180 nozzles for each of cyan1, cyan2, magenta1, magenta2,
yellow1, and yellow2)
Nozzle pitch: 0.141mm (1/180 inch) for each color
Table 2-2. Relationship between Nozzle Rows and Colors
Nozzle Row 8-Color Mode
A Light gray
B Light magenta
C Light cyan
D Gray
E Photo black/Matte black
F Cyan
G Magenta
H Yellow
Operating Principles
Figure 2-1)
0.071mm
1/360inch
Drive waveform:
The following table shows the outline of the waveforms of the six print modes.
4-Color Mode
Waveform Name
Matte black
Matte black
VSD1
Magenta
Magenta
VSD1d
Cyan
Cyan
VSD2
Yellow
Yellow
VSD2d
VSD3
VSD3_HR
Print Mechanism Components
2.258mm 2.258mm 2.258mm
64/720inch 64/720inch 64/720inch
7.620mm 7.620mm 7.620mm
216/720inch 216/720inch 216/720inch
F#180
B#180 D#180
A#180 C#180 E#180
F#179
D#179
B#179
C#179 E#179
A#179
F#178
B#178 D#178
E#178
A#178 C#178
F#3
D#3
B#3
A#3
C#3 E#3
F#2
D#2
B#2
A#2
E#2
C#2
B#1 F#1
D#1
A#1 C#1 E#1
31.89mm
41.66mm
Carriage Moving Direction
Figure 2-1. Nozzle Arrangement
Table 2-3. Printing Modes (Drive Waveforms)
Drive Frequency Print Resolution
H360 x V360
11.52 KHz ± 7% H360 x V720
H720 x V360
H360 x V360
11.52 KHz ± 7% H360 x V720
H720 x V360
H720 x V360
±
8.64 KHz 7%
H720 x V720
H720 x V360
±
8.64 KHz 7%
H720 x V720
H720 x V720
8.64 KHz ± 7%
H1440 x V720
±
8.64 KHz 7% H2880 x V1440
Revision B
2.258mm
64/720inch
H#180
G#180
H#179
G#179
H#178
G#178
0.041mm
H#3
G#3
1/180inch
H#2
G#2
H#1
G#1
CR Speed
320 CPS
320 CPS
240 CPS
240 CPS
240 CPS
240 CPS
150