Printhead Controller/Driver Circuit - Epson DLQ-3000 Service Manual

Operating Principles

2.3.9 Printhead Controller/Driver Circuit

Figure 2-19 shows a block diagram of the Printhead controller/driver circuit.
This printer is equipped with 24 head coils (12x
coil driver circuit.
Each coil is driven by its two transistors (PNP and NPN) and a MCSFET. The transistors supply
common currents VPA and VPB, and the MOS-FET connects and disconnect ground GP, and they
drive the coil with different timing. This is to increase the response speed of the head pin by
driving coil T after the MOS-FET is turned off.
The data from the host computer is expanded into image data (CG data) and latched in the E05A88
Allocation of the head data is performed in the E05A88. The latched data is output by the internal
processing of E05A88.
Table 2-26. Printhead Controller/Driver Circuit Specifications
Item
Source Voltage
Drive Current
Response Period
CPU
DRESSI
IATA BUS
Print Pulse A
Print Pulse B
Figure 2-20. Printhead Drive Mechanism
2-26
lines), and the driver circuit is a constant current
2
VDC * 107.
35
Max. peak current (at 5'C ) 3.3A/ pin
463 sec. ( 2.16 KHz) at 5 'C, Copy 2 mode
PHPW
NHPW
PRE-
DRIVER
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Print Pulse A
Head Coil
Print Pulse B
Print Head Drive
Waveform
Content
w
PRINTHEAD
DRIVER
(QM2-6,1O) ;
T
I