Hardware - Epson ELP-3500 Service Manual

2.1 HARDWARE

The optical and electrical systems are the major areas of projector hardware. The lower
level (below the broken line in the figure) shows the optical system, and the upper level
shows the electrical system.
POWER
SUPPLY UNIT:
Generates DC
voltages
(+5 V +18 V) for
the electric
circuits. Also
generates DC
voltage (+65 V)
for the light
source.
EXHAUST FAN *2
LAMP
HOUSING:
150 W - 65 V
light source.
Description of the Projection Process
1. A video signal is provided in digital or analog form from a computer through the
interface board. (Analog signals are converted into digital signals by the main board.)
2. The digital video signal is then stored in video memory on the main board. Then the
driver board generates signals to drive the R/G/B light valves.
3. The R/G/B light valves are individual panels, independent of each other. They work
to shut off or transmit light from the light valve block.
4. Lights transmitted through the light valves are combined by a prism and projected
through the lens unit.
MAIN BOARD:
Generates the R/G/B light
valves' memory and the
drive signals. Sets initial
operations for interface
circuit and controls
sensors, fans, speakers,
and remote control.
INTAKE FAN *1
Note: *1 The intake fan cools the R/G/B
LIGHT VALVE
BLOCK: Divides the
light into 3 parts
Note: *2 The exhaust fan mainly gives off
(R/G/B) for the lens,
filter, and mirror
Figure 2-1.
2-1
DRIVER BOARD:
Generates the
R/G/B video
signal.
Detects the
brightness and
controls the
temperature.
(overheating
protection).
R/G/B LIGHT R/G/B
VALVES PRISM
composite
light valves of the LCD panel.
heated air from around the light
source.
IINTERFACE
UNIT:
I/O interface
connector
board (PC /
video / audio /
RS-232 /
remote / DC
OUT)
LENS UNIT
Focus/Zoom