Polaroid SprintScan SS35 Repair Manual page 35

Slide Scanner Repair Manual
Component
Image Sensor PC Board
Video Signal
Processor (VSP)
Analog-to-Digital
(A/D) Converter
Primary Correction ASIC
Buffer
Table 2-1. Component Functions (Cont'd)
Provides biasing and clocking for the CCD array. It
also buffers the CCD outputs and multiplexes them
onto a single line.
The VSP processes the buffered analog signal. It
contains a preamplifier with voltage controlled gain, a
correlated double sample with offset adjustment, and
an output amplifier.
The VSP also contains three individually controlled
sample-and-hold amplifiers and two 3-to-1 multiplexers
which facilitate dark level adjustment and white
balance correction.
Converts the processed analog signal from the VSP
into a digital RGB image signal.
Note: 10-bit A/D converter for SS35/SS35 ES, 12-bit
Primary correction is performed by this ASIC. It
concentrates on all processing which can be
performed on a single channel of red, green, or blue
data.
It corrects the brightness, contrast, and color balance
of the RGB image data signal from the A/D converter,
using uniformity correction factors (dark level
uniformity, brightness correction, and uniformity gain
correction) stored in its memory and then sends
corrected RGB image data to the color correction
ASIC.
Separates (buffers) the two processing ASIC's. It is
used to realign the three colors and serve as a
transfer buffer between the synchronous data
generation by the CCD image sensor and the
asynchronous host SCSI data transfer.
Functions
A/D converter for SS35 PLUS.
35
Functional Description