Print Head Control Circuit - Epson 440 Service Manual

2.2.2.6

Print Head Control Circuit

The print head control circuit of Stylus Color 600 has following characteristics.

Common waveform circuit became one HIC.

Micro-vibration mode is added.(when the CR motor is accelerating)

High speed drive 14.4KHz (trapezoidal wave form

Enhanced Nozzle configuration (resolution in the vertical direction)90dpi
(However, black nozzle is 2 lines structure)
Also, Stylus Color 600 has Micro-dot control as dot shooting control. There are total three dot shooting
controls on this printer.
Normal Dot mode(Single Firing)
•
Normal Dot mode(Dual Firing)
•
Micro Dot mode
•
Micro-Vibration(Not printed)
•
The control circuit is considered as two divided parts; 1) trapezoidal wave form generation circuit
(common drive circuit) to drive PZT in the head, and 2) Nozzle-selector drive circuit to determine
which nozzle should be used. The Nozzle-Selector is attached to the head unit just like the previous
models. The common drive circuit is became as HIC and mounted on the C200 main board.
[Common drive circuit]
Figure 2-24. Print Head Control Circuit Block Diagram
The shape of trapezoidal wave form will be different according to the printing operation, slight vibrations at
the non-printing nozzle and waiting condition. However, IC7(H8D2813) generates all wave forms as drive
wave forms by resistance(electric) welding control of common voltage drive control signal that is output
from the IC2(E05B43) in the figure above.
Item
Power Voltage
Final drive element
Reset Operation
This common voltage trapezoidal wave form can be observed anytime after the +5V rises even if there is
printing data or not. (Q7:3-pin, or Q9:3-pin and GND on the C200 main board)
Rev. A
Table 2-13. Specifications of H8D2813 Operation
42•}5%
Starts supplying after 5V rises and be stabilized./ Stops
supplying before +5V drops.
2SC3746(for charging), 2SA1469(for discharging)
Off on the both charging and discharging sides.
Supplies drive power source.
Chapter2 Operating Principles
Contents
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