PI214MC-DR Datasheet, PDF (2/8 Pages) AMI SEMICONDUCTOR – 200DPI CIS Two Level Digital Output Module

• Where data compression is required, such as in data transmissions.
• Where component pin-out count must be kept to a minimum.
The background-tracking-digitizing circuits in the PI214MC-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
1726
1728
1727
5 ----------------
VIDEO
LINE
BUFFER
SHIFT REGISTER
VIDEO
AMP
TRACKING DIGITIZER
VN(-V)
VDD (+5)
GRD
DIGOUT
CP
SP
GRD
Figure 1. PI214MC-DR Module Block Diagram.
The PI214MC-DR module consists of 27 sensors that are cascaded to provide 1728
photo-detectors with their associated multiplex switches, and a digital shift register that
controls its sequential readout. Mounted in the module is a 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 PI214MC-DR module.
Illumination is by means of an integrated LED light source. All components are housed
in a small plastic housing which has a cover glass which acts as the focal point for the
object being scanned and protects the imaging array, micro lens assembly, and LED
light source from dust. The pictorial of PI214MC-DR cross section is shown, below, in
Figure 2.
Page 2 of 8 PI214MC-DR, 11/29/99