PI331MC-DR Datasheet, PDF (2/9 Pages) AMI SEMICONDUCTOR – 300DPI CIS Two Level Digital Output Module

• Where component pin-out count must be kept to a minimum.
The background-tracking-digitizing circuits in the PI331MC-DR have been referred to as
the “dynamic threshold” two-level A/D converter. For the purpose of describing the
module’s characteristics this “dynamic threshold” processing circuit shall herein be
referred to as the “tracking digitizer”.
Module Description
GLED
VLED
LED
LED
LED
LED
LED
LED
LED
LED
12
34
ROD LENS
PHOTO SENSORS
1054
1056
1055
5 ----------------
VIDEO
LINE
BUFFER
SHIFT REGISTER
VIDEO
AMP
TRACKING DIGITIZER
VN(-V)
VDD (+5)
GRD
DIGOUT
CP
SP
GRD
Figure 1. PI331MC-DR Module Block Diagram.
The PI331MC-DR module consists of 11 sensors that are cascaded to provide 1056
photo-detectors with their associated multiplex switches, and a digital shift register that
controls its sequential readout. Mounted in the module is one-to-one graded-indexed
micro lens array that focuses the scanned documents to image onto its sensing plane. A
buffer amplifier amplifies the video pixels from the image sensors and passes them to
analog digitizing circuit, where video pixels are converted to digital signal and passed to
output of the module. See Figure 1, the block diagram of the PI331MC-DR module.
Illumination is by means of an integrated LED light source. All components are housed in
a small plastic housing with a cover glass which acts as the focal point for the object being
scanned and protects the imaging array, the micro lens assembly, and the LED light
source from dust. The pictorial of PI331MC-DR cross section is shown in Figure 2.
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