Figure 2-27. Color Upgrade Kit Connector Pin Alignment; Figure 2-28. Color Data Transmission Timing - Epson Stylus 1500 Service Manual

Stylus 1500 Service Manual Operating Principles
2. Color Ink Printing
Common driver circuit
The color printing common voltage (VH) is established to correspond to each of the color printhead
characteristics. This value is stored in ID1 - ID4 patterns in each printhead driver circuit. By connecting the
color printhead unit (color upgrade kit) to the carriage unit, these ID data are transmitted to the C172 MAIN
Board by the printhead harness. The E05B16 gate array (IC2) outputs the parallel data of the voltage control
signals (CHPWMO) to the common driver circuit referring to this value. The common voltage is then
established at 15 levels of the 24 V center value.
G N D 2
G N D
S I
C L O C K
G N D
ID 1
I D 2
I D 4
I E
C O
T H
L A T C H
F G
C O M
V D D
M / C
I D 3
G N D

Figure 2-27. Color Upgrade Kit Connector Pin Alignment

Head driver circuit
The print data is converted into serial data by the E05B16 gate array (IC2) and is output from port BHSO (pin
56) to the black head driver circuit. Head driver SED5619D then latches the head data when the E05B16 gate
array (IC2) outputs the CHLAT signal, and the latched data becomes 60-bit parallel data for the color head.
One bit corresponds to each nozzle.
When data transfer and nozzle selection are complete, the E05B16 gate array (IC2) outputs the color head
charge pulse (CH2C) and discharge pulse (CH2D1/0) to the common drive circuit. The common drive circuit
then generates the trapezoidal pulse and applies it to the printhead as a common drive pulse. After this, the
nozzle selected by the head data is activated to eject the ink.
CHSO
# 1
# 6 4
CHCLK
CHLAT
V H
COM
C H 2 C
CH2D1/0

Figure 2-28. Color Data Transmission Timing

Rev. A 2-23