Printhead Driver Circuit - Epson Stylus PHOTO 2000P Service Manual

EPSON Stylus PHOTO 2000P

2.2.2.1 Printhead Driver Circuit

The printhead driver circuit includes:
Common driver IC IC10 (E09A14RA)/IC10 (E09A15KA) directly
attached to the C304MAIN board.
Nozzle selector IC (IR2C95F or SED6125T0A) on the head board.
The common driver generates reference drive waveforms according to
the output signals from ASIC on the C304MAIN board. The reference drive
waveforms are amplified by the transistors Q3 and Q4 and then
transferred to the nozzle selector IC on the head board. Print data is
converted to serial data by the ASIC and then also sent to the nozzle
selector IC on the head board. Based on the serial data, the nozzle selector
IC determines the nozzles to be actuated. The selected nozzles (PZT) are
driven according to the drive waveforms produced by the common driver.
See Figure 2-14 for the printhead driver circuit block diagram.
Head common driver circuit
The head common driver IC10 (E09A14RA)/IC10 (E09A15KA)
generates reference head drive waveforms according to the output of
the following 9 signal lines: A0-A4, CLK1, CLK2, RST, FLOOR, and
DATA.
By the DATA signal output from the IC8 ASIC (E05B70**), the original
data for the head drive waveform is written in the memory in the IC10/
IC11. Addresses for the written data are determined by the A0 - A4
signals, and, of among, data used to determine the waveform angles
is selected. Then, setting the selected data, producing trapezoid
waveform value, and canceling the data are performed by the rising
edges of the CLK1 and CLK2 signals.
Head nozzle selector circuit
Print data is converted into serial data by the ASIC (E05B70**). Then
the converted data is allocated to the six rows, the number of the
head nozzle rows, to be transferred to the nozzle selector IR2C95F
(Sharp) or SED6125T0A (EPSON) through the six signal lines (HS01 to
HS06). Data transmission from IC8 ASIC (E05B70**) to the nozzle
selector synchronizes with the LAT signal and SCK clock signal.
Referring to the transferred data, The nozzle selector IC selects the
nozzles to be activated, and the PZTs of the activated nozzles are
driven by the drive waveforms output from the head common driver.
OPERATING PRINCIPLES
HWA0
HWA1
HWA2
HWA3
HWA4
HWCLK1
HWCLK2
HWFLR
HWRST
HWSDATA
HWSCLK
HWSLAT
IC 8 ASIC
E05B70CD
HCH
HLAT
CRAI0
CRAI1
SWCO
SWC1
HS01
HS02
HS03
HS04
HS05
HS06
HSOCMD
HNCHG
HSOCLK
to CPU AN0 port
Electrical Circuit Operating Principles
F1
VCC COM
AO
COM
A1
NPNB
COM
A2
FB COM
A3
PNPB VHV
A4
CLK1 VHV
CN8
CLK2
FLOOR
RST CH
DATA LAT
DCLK ENA
ENB
E
IC10
Commom
Driver IC
Nozzle Selecor IC
IR2C95F
COB
COA
SI1
SI2
SI3
SI4
SI5
CN9 CN9
SI6
SP
NCHG
SCK
THM
Figure 2-14. Printhead Driver Circuit
Revision A
Head Drive Pulse
48