EPSON Stylus COLOR C70/C80
Revision A
Operating Principles
Electrical Circuit Operating Principles
56
2.2.2.2 Printhead Driver Circuit
The printhead driver circuit consists of the following two components:
Common driver IC (IC13 : E09A38RA) directly attached to the C424 MAIN-
B board.
Nozzle selector IC on the head board.
The common driver (IC13 : E09A38RA) generates a reference drive waveform
according to the output signals from the C424 MAIN-B board. The reference
drivewaveform is amplified by the transistors Q9 and Q10 and then transferred to the
nozzle selector IC on the head board. Print data is converted to serial data by the CPU
(IC7) and then 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
are driven by the drive waveforms produced by the common driver. See Figure 2-28
for the printhead driver circuit block diagram.
Head common driver circuit
The reference head drive waveform is produced in the common driver (IC13 :
E09A38RA) based on the following 12 signal lines output from the ASIC (IC7 );
A0-A4, CLK1, CLK2, FLOOR, RST, DATA, DCLK, and E.
By the DATA signal output from the CPU (IC7), the original data for the head
drive waveform is written in the memory in the IC13. The 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
Printing data is converted into serial data by the CPU (IC7). Then the converted
data is allocated to the six rows, the number of the head nozzle rows, to be
transferred to the nozzle selector through the seven signal lines (HS01 to HS07).
Data transmission from the CPU (IC7) to the nozzle selector synchronizes with the
LAT signal and SCK clock signal. Referring to the transferred data, nozzles to be
activated are selected, and the PZTs of the selected nozzles are driven by the drive
waveform output from the head common driver.
Abnormal tempertature detection circuit
Feed back signal from Pin12 and Pin10 in Cn9 are used to head tempertature
detection. If the temp. inside the head increases 120
°
C, Printer stops current
printing, then make either black or color (YMC) ink cartridge set to ink out.
Figure 2-28. Printhead Driver Circuit
IC7 CPU
E01A27CA
IC13 CPU
Common
Pre-Driver
HWA0
HWA1
HWA2
HWA3
HWA4
HWCLK1
HWCLK2
HWFLR
HWRST
HWSDATA
HWSCLK
HWSLAT
27
28
29
31
32
33
22
21
20
26
25
24
28
27
26
25
24
3
4
5
6
30
1
29
A0
A1
A2
A3
A4
CLK1
CLK2
FLOOR
RST
DATA
DCLK
E
DAOUT
VCC45
NPNB
FB
PNDB
VCC5
I/O
DP8
DP6
DP7
DP5
DP4
DP3
DP2
DP1
GND5
GND45
VOUTGND
22
20
18
16
23
2
21
19
17
15
13
12
11
9
7
10
14
2
4
6
8
25
24
22
20
14
COM
COM
COM
COM
COM
COM
COM
LHT
VHV
CN8
CN9
8
+42V
+5V
F1
HLAT
HCH
HNCHG
HSOCLK
HSOCMD2
HSOCMD1
C-P41
C-P42
51
50
52
48
46
47
56
57
8
16
6
2
4
12
10
CH
NCHG
SCK
SI2
SI1
AND1
AND2
COM
18
Summary of Contents for Stylus Color C70
Page 1: ...EPSONStylusColorC70 C80 Color Inkjet Printer SEIJ01 004 SERVICE MANUAL ...
Page 5: ...Revision Status Revision Issued Date Description A July 31 2001 First Release ...
Page 9: ...C H A P T E R 1 PRODUCTDESCRIPTION ...
Page 35: ...C H A P T E R 2 OPERATINGPRINCIPLES ...
Page 60: ...C H A P T E R 3 TROUBLESHOOTING ...
Page 96: ...C H A P T E R 4 DISASSEMBLYANDASSEMBLY ...
Page 137: ...C H A P T E R 5 ADJUSTMENT ...
Page 169: ...C H A P T E R 6 MAINTENANCE ...
Page 182: ...C H A P T E R 7 APPENDIX ...
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