Epson PhotoPC 850Z, Service Manual, Page: 39 / 127

EPSON PhotoPC 850Z Revision A
Operating Principles Overview 39
2.1 Overview
Major component of PhotoPC 850Z consists of electric circuit and the Lens
Assy. The figure below shows layout of the major electric boards.
Figure 2-1. Major Component
Lens Assy.
Includes the Optical Zoom Mechanism, Shutter Mechanism, Aperture
Mechanism, and Focus Mechanism.
Lens Focus Distance: 6.5 - 19.5mm
Lens Construction: 8 elements in 6 groups
Electric Circuit
The electric circuit consists of CA1, CA2, SY1, SY2, ST1, TB1, TB2, and
PW1 Boards. The table below shows functions of each board.
Table 2-1. Board Function
Board Function
CA1
CCD image sensor interline type
• CCD clock drive
• A/D conversion of image data
• Drives the Lens Assy.
(shutter, aperture, focus, and zoom)
CA2
Consists of RISC-CPU, ASIC, 8Mbit Flash-ROM, 32Mbit
SDRAM.
• Digital clamp
•
γ
correction, color generation, matrix, horizontal and
vertical aperture
• SDRAM controller
• USB control
SY1
8 bit microprocessor
• Operation key input
• Controls LCD panel display
• Controls the power circuits
• Controls the flash charging
SY2 LED in the Viewfinder
ST1 Controls the external flash.
TB1 Battery circuit
TB2
Barrier switch board
• Monitors opening/closing of the barrier
PW1
Power Circuit
• Switch controller, short-circuit protection circuit
• Digital 5V and analog system power output
• Digital 3.25V system power output
• LCD system power supply
• Backlight power supply output