Printhead Driver Circuit - Epson Stylus Color 1520 Service Manual

EPSON Stylus COLOR 1520

2.3.2.5 Printhead Driver Circuit

This printer has 2 separate printhead driver circuits, one for the black printhead and one for the color
printhead. Each circuit has the common voltage driver circuit attached to the main board and the nozzle
selection circuit attached to the printhead driver circuit board. The common driver circuits for the both black
and color printheads are composed of the hybrid ICs (IC19) and the terminal transistors. A 128-bit transfer
gate array IC IR2C72C is used for the black printhead nozzle selection circuit. A 128-bit transfer gate array
IC IR2C72C (for cyan and yellow) and a 64-bit transfer gate array IC IR2C73C (for magenta) are used for the
color printhead nozzle selection circuit. Printing data is separated into a common voltage signal and nozzle
selection signal at the gate array E05B33 (IC6) and is then transferred to the corresponding circuit. Figure 2-
24 shows the printhead driver circuit block diagram.
E05B33 (IC6)
BCHG,BKC
BND0/1,BMD0/1
SBDATA
BHCLK
BHLAT
BA/BHDATA
BHNCHG
VHPR
SCLK,SSTB,SCLR
CCHG,CKC
CND1/2,CMD1/2
SCDATA
CHCLK
CHLAT
YHDATA
CHDATA
MHDATA
CHNCHG
C211 Main Board
2-24
Common Driver
Common Driver
Figure 2-24. Printhead Driver Circuit Block Diagram
IR2C72C
COM
CLK
LAT
SI
NCHG
VHV
IR2C72C
COM
CLK
LAT
S3
S1
NCHG
VHV
IR2C73C
COM
CLK
LAT
S2
VHV
Printhead Driver Circuit
Black
Cyan
Yellow
Magenta