Epson 440 User Manual

Page 75

EPSON Stylus Color 440/640/740

Revision A

Chapter 2

Operating Principles

Figure 2-34. Head Drive Circuit for Stylus Color 740

[Common drive circuit]
The shape of trapezoidal wave form will be different according to the
printing operation, slight vibrations at the non-printing nozzle and
waiting condition. However, the IC6(for Stylus Color 440), IC7(for Stylus
Color 640), IC14(for Stylus Color 740) generates all wave forms as
drive wave forms by resistance(electric) welding control of common
voltage drive control signal that is output from the IC2(gate array) in the
figure above.

Table 2-9.

Specifications of H8D2813/CXA20995 for Stylus Color 440, 640, 740

This common voltage trapezoidal wave form can be observed anytime
after the +5V rises even if there is printing data or not. (Q7:3-pin,Q9:3-
pin for Stylus Color 440 and Q2: 3-pin, Q3: 3-pin for Stylus Color 640,
740)

[Nozzle Selector Drive Circuit]
In order to motivate the print head to carry out printing, it is necessary to
transmit the printing data to the appropriate nozzles, which becomes
direct signals to drive PZT. This data transmission is performed by the
serial method, however the data output for each black and CMY head is
transmitted by the parallel method.

CXA20996(IC14)

VCC45
Vcc45_2
NPNB
FB
PNPB

VOUTGND

E05B588(IC2)

VHCTL

CCO

LAT

CLK

BCO

THM

190

SWC0

184

HLAT

IECLK

AN0

105

A0
A1
A2
A3
CLK1
CLK2
/FLOOR
/RST
DATA
DCLK
/E

HWA0
HWA1
HWA2
HWA3
HWCLK1
HWCLK2
/HWFLR
/HWRST
HWSDATA
HWSCLK
/HWSLAT

SI1

174

HNCHG

+42

GND2

COM

VHV

VCC5

SWC1

189

173

NCHG

HCLK

175

176

HSI1

SI2

HSI2

177

SI3

HSI3

178

SI4

179

HSI4

SI5

HSI5

180

SI6

HSI6

181

TMP95C061(IC1)

GND

CN9

Items

COntents

Drive Power Voltage

Starts supplying after 5V rises and be stabilized./

Stops supplying before +5V drops.

Final Drive Element

2SC3746(for charging),
2SA1469(for discharging)

Operation at the Reset

Off on the both charging and discharging sides.

Supplies drive power source.