Epson PhotoPC 850Z Service Manual page 46

EPSON PhotoPC 850Z
SIGNAL PROCESSOR

γ Correction Circuit
This circuit performs (gamma) correction in order to maintain a linear
relationship between the light input to the camera and the light output from
the picture screen.

Color Generation Circuit
This circuit converts the CCD data into RGB signals.

Matrix Circuit
This circuit generates Y signals, R-Y signals and B-Y signals from the RGB
signals.

Horizontal and Vertical Aperture Circuit
This circuit is used to generate the aperture signal.
AE/AWB AND AF COMPUTING CIRCUIT
The AE/AWB carries out computations based on a 64-segment screen, and the
AF carries out computations based on a 6-segment screen.
SDRAM CONTROLLER
This circuit outputs address, RAS, CAS, and AS data for controlling the
SDRAM. It also refreshes the SDRAM.
COMMUNICATION CONTROL

USART
The RS-232C can be sued for both synchronous and asynchronous
transmission.

SIO
This is the interface for the 4-bit microprocessor.

PIO/PWM/SIO for LCD
8-bit parallel input and output makes it possible to switch between
individual input/output and PWM input/output.
Operating Principles
TG/SG
Timing generated for 2 million pixel CCD control.
DIGITAL ENCODER
It generates chroma signal from color difference signal.
Operating Principles of Circuit Boards
Revision A
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