AMI PI330MC-DR

™
Peripheral
Imaging
Corporation
PI330MC-DR
300DPI CIS Two Level Digital Output Module
Engineering Data Sheet
Key Features
• Light source, lens, and sensor are integrated into a single module
• 11.8 dpm resolution, 89 mm scanning length
• Up to 423 µsec/line scanning speed, with 2.5 MHz pixel rate (See Table 3, Note 3.)
• Wide dynamic range
• Two-Level Tracking Digital Output (“Dynamic Threshold Digitizer”)
• Infrared light source 880nm (Other colors are available)
• Compact size ≅ 15 mm x 25.6 mm x 102 mm
• Low power
• Light weight
General Description
The PI330MC-DR is a contact image sensor, CIS, module with an additional on board
circuit that digitizes the analog pixels from the CIS image sensor to a “backgroundtracking”, two-level digital output signals. It is based on CIS module, the PI305M-A6
manufactured by PIC, but with a shorter read length of 89 mm. Hence, its performance is
equivalent to the PI305M-A6 that uses MOS image sensor technology to gains its highspeed performance and high sensitivity. The PI330MC-DR is suitable for scanning
documents with width of 89 mm and with resolution of 11.8 dots per millimeter. Its has a
broad applications, but specially designed for the following areas:
• Where data compression is required, such as in data transmissions.
• Where component pin-out count must be kept to a minimum.
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The background-tracking-digitizing circuits in the PI330MC-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
LED
LED
LED
LED
LED
LED
LED
LED
VLED
ROD LENS
1054
PHOTO SENSORS
1
2
3
4
5
1055
1056
----------------
VIDEO
LINE
VN(-V)
VDD (+5)
SHIFT REGISTER
GRD
BUFFER
VIDEO
AMP
CP
SP
TRACKING DIGITIZER
DIGOUT
GRD
Figure 1. PI330MC-DR Module Block Diagram.
The PI330MC-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 PI330MC-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 PI330MC-DR cross section is shown in Figure 2.
PAGE 2 OF 9 - PI330MC-DR, 4/13/00
DOCUMENT SURFACE
GLASS WINDOW
ROD LENS
MODULE HOUSE
LIGHT PATH
D
LE
R
BA
SENSORS
PCB
Figure 2. PI330MC-DR Module Cross Section
I/O to the module is a 8-pin flex cable connector (See I/O Connector, under
Specifications) located on one end of the module. The connector is on the top of the
module with the glass window facing down and it is located on the opposite side of the
module. See the Mechanical Housing under Mechanical Structure.
Circuit Description and Operation
See Figure 3 a simplified block diagram of the analog tracking digitizer. Fundamentally,
the tracking digitizer transforms the signal output from a CIS module existing on the
IMAGE
PIXELS
TWO
LEVEL
COMPARATOR
FROM
THE
CIS
DIGITAL
OUTPUT
REFERENCE
LEVEL
GENERATOR
FIGURE 3. ANALOG SIGNAL REFERENCE
GENERATOR AND A SINGLE BIT COMPARATOR
market today. It takes the analog signal from the CIS section of PI330MC-DR and derives
a tracking background reference signal. Then this reference is compared against the
output signals from the CIS section. The resulting signal from comparison produces a twolevel digital signal that is high when the pixel signal is brighter than the background and
remains at zero as long as the signal is darker than the background signal.
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Figure 1, PI330MC-DR block diagram depicts the two basic circuits, the CIS (image
sensors and video amplifier) and the tracking digitizer. In the CIS section, the module has
11 serially concatenated PI3012A image sensors, accordingly, the image sensors will
span one scanning-read line width that is 11 sensor times 96 pixel elements/sensor, or
1056 pixel elements.
In operation the module produces the analog image pixel signals that are proportional to
exposure on the corresponding picture element on the document (the video signal) then
passes the signal to the tracking digitizer. In turn, the digitizer processes the analog image
pixels to digital image pixels. The analog image pixels, at test point TV, are separated into
two signals. One generates the reference signal and the other remains unmodified. These
unmodified image pixels are applied to one of the input of the comparator. The reference
signal is applied to the second input of the comparator. The results of the comparison are
the digital image pixels. This digital output is produced in two levels, determined by the
difference between the background reference signal and the analog image pixels. A digital
pixel output of value “one” represents the analog image pixel that is brighter than the
background and digital pixel level of value “zero” represents the image pixel that is darker
than background.
Specifications
I/O Connector
The table of pins and their functions are listed in Table I, Pin Configuration.
Pin Number
1
2
3
4
5
6
7
8
Symbol
DIGOUT
Vdd (+5 V)
Vn (-10 to -5V)
SP
GRD
CLOCK
GLED
VLED
Names and Functions
Digital Video Output
Ground; 0 V
Negative power supply
Start Pulse for the shift register
Ground; 0 V
Clock for the shift register
Return for the LED light source
Power in for the LED light
source.
Table 1. Pin configuration
The connector is a 8-pin 1-mm surface mount flex input, Molex 52207-0890.
Inputs:
There are five inputs:
• Clock is on Pin 6 of the I/O Connector. This is main clock input into the CIS Module.
• SP is on Pin 4. This is the start clock input to the CIS Module.
PAGE 4 OF 9 - PI330MC-DR, 4/13/00
• VDD is on Pin 2. This is a + 5 Volts supply.
• VN is on Pin 3. This is a (– 10 to –5) Volts supply.
• VLED is on Pin 8. This is a +24 Volts supply for the LED light source.
Note: Power return for the LED light source is GLED on Pin 7 and the ground return for
the CIS modules is pin 5.
Video Output:
DIGOUT is on pin 1 of the I/O connector. This is the digital video output from the CIS
module. Reflection off the dark target produces a digital signal of “0” level, while the white
reflection off the white target produces a digital level of “one”. The amplitudes of the white
and dark are listed in the table below:
Electro-Optical Characteristics (25° C)
Table 2. Electro-optical characteristics at 25° C.
Parameter
Symbol
Number of photo detectors
Pixel to pixel spacing
Line scanning rate
Tint (1)
Parameter
1056
84.7
528
Units
elements
µm
µsec
Clock frequency
Bright output
Dark output
2.0
>3.2
<0.8
MHz
Volts
Volts
f
Digital Video
Output Signal
Note
@ 2.0 MHz
clock
frequency
(1) The Tint is specified with a 2.0 MHz clock frequency. In operation the time
constants in the reference generator is set to match the initial exposure time,
hence the time constant will determine the optimum integration time. Note the
integration time is also a function of the clock frequency. Accordingly it is highly
recommended that the parameters be factory adjust for the specific
applications.
Table 3. Recommended Operating Conditions (25 °C)
Item
Symbol
Min
Power Supply
Vdd
Vn.
-10
VLED
Idd
Ivn
ILED
Input voltage at digital high
Vih
Vdd-1.0
Input voltage at digital low
Vil
0
Clock frequency
f
Clock pulse high duty cycle
25
Clock pulse high duration
Clock
100 (2)
Mean
5.0
Max
-5
24 (1)
25
15
60
Vdd-.5
PAGE 5 OF 9 - PI330MC-DR, 4/13/00
Vdd
0.8
2.5
Units
V
V
V
mA
mA
mA
V
V
MHz
%
ns
Integration time
Tint
0.423 (3)
ms
0
Operating temperature
Top
25
50
C
Note:
(1) VLED sources are also available in 5 Volts.
(2) Clock pulse high is specified at 2.5 MHz at 25% duty.
(3) The Tint is specified with a 2.5 MHz clock frequency. In operation the time
constants in the reference generator is set to match the initial exposure time,
hence the time constant will determine the optimum integration time.
Accordingly it is highly recommended that the parameters be factory adjust for
the specific applications
Switching Characteristics (25°C)
The switching characteristics for the I/O clocks are shown in Figure 4, Module Timing
Diagram. The timing parametric values and their symbols are given in the Table 4.
to
tw
CP
tprh
SP
tdh
tds
tdl
Vanalog
tsh
tddl
tdodl
Digout
MODULE TIMING DIAGRAM
FIGURE 4
Table 4. Switching Parameter and Timing Symbol Definition
Clock cycle time
Clock pulse width
Clock duty cycle
Prohibit crossing time
of Start Pulse
Data setup time
Data hold time
Signal delay time
Signal settling time
Symbol
to
tw
Min.
tprh
100
25
15
tds
tdh
tdl
tsh
20
20
50
120
Typical
0.50
PAGE 6 OF 9 - PI330MC-DR, 4/13/00
Max.
50
Units
µs
ns
%
ns
ns
ns
ns
ns
Digital Signal Delay
Digital Signal Off
Delay
tddl
tdodl
60
300
Table 5 Absolute Maximum Rating:
Parameter
Symbols
Power supply voltage
Input clock pulse (high level)
Input clock pulse (low level)
Table 6 Operating Environment
Operating temperature
Operating humidity
Storage temperature
Storage humidity
ns
ns
Units
Vdd
Idd
Vn
In
VLED
ILED
Vih
Vil
Maximum
Rating
10
50
-15
30
25
80
Vdd – 0.5
-0.8
Top
Hop
Tstg
Hstg
0 to 50
10 to 85
-25 to+75
5 to 95
0
V
mA
V
mA
V
mA
V
V
C
%
0
C
%
Setup and Adjustments
The Clock Rate and Integration Time:
This was factory set to a specific application. See note 1 under Table 2, Electro-optical
characteristics at 25° C.
The clock frequency was set to 2.4 MHz.
The total integration time was set to 560 µsec.
The Required Power.
The required power is slightly greater than the specified values in Table 3.
Circuit Power:
Positive Supply:
Negative Supply:
LED Power:
+5 Volts @ 25 mA
-10 Volts @ 15 mA
+24 Volts @ 60 mA
PAGE 7 OF 9 - PI330MC-DR, 4/13/00
Adjustments
General Location of Test, Adjustment and Monitor Points
BACK SIDE OF THE PCB AS VIEWED ON MODULE
WITH THE GLASS WINDOW FACING DOWN.
TV
R5 (Gain Adj)
TR
TVD
R4 (Offset Adj)
Connector
VLED
GLED
PI330MC-DR PCB Monitor & Test Points
FIGURE 5
Figure 5, PI330MC-DR PCB MONITOR AND TEST POINTS, shows the pictorial layout of
the controls and the tests points. These adjustment potentiometers and the test points are
shown relative to the connector and to the output pads for LED light power. This is a bird’s
eye view of the PCB’s backside with the glass window of the module facing down on the
documents.
Test point labeled TV is for the analog image pixels, just as it is produced at the output of
the CIS array section, and prior to its entry into the tracking digitizer circuit.
Test point labeled TR is the output of the tracking reference level from the tracking
digitizer circuit.
Test point labeled TVD is the digital output from the comparator.
Offset adjust, R4, is a screw driver adjustment potentiometer that is accessed through
adjustment hole as it viewed in figure 5.
Gain adjust, R5, is a screw driver adjustment potentiometer that is accessed through the
hole as it is viewed in figure 5.
There are only two adjustments:
These adjustments will be pre-adjusted to the customer’s specific application at the
factory, therefore, in general will not require adjustments by the user.
PAGE 8 OF 9 - PI330MC-DR, 4/13/00
The gain is adjusted by monitoring test point TV with a scope, adjusting the gain
potentiometer, R5, until the analog image pixel levels are set to approximately 2.0 volts
peak with the module imaged on the a standard white target similar to the standard white
copy or typing paper. (The probe should be grounded as close to the CIS module as
possible. If possibly right on the ground input lead, pin 5, of the I/O connector.)
Then DC reference level is adjust by monitoring test point TR and setting the voltage to
approximately 1.6 Volts by adjusting offset potentiometer, R4.
Mechanical Structure
e
on
NOTE:
All dimensions in mm
ez
v
cti
ina 0
e
1
t
r
nte tor
.0 e ce nec
5
1 th on
to he c
t
of
a
xim
ro
pp
ne
ve
cti
m
a
zo
2 m
10 imu
x
a
m
ina
4m
ma 25.
xim 6
um
2 sets of mounting holes are
mirror imaged on both ends
Hole = 2x2 M1.8 Top Tight Screw
8.0
14
.0
1mm x 8 Flex
cable connector
22.00
22
.0
7.1
14.0
16.5
6.8
24
.6
Readline
6.0
24.3
25.3
FIGURE 6 MECHANICAL STRUCTURE
Figure 6 is pictorial of the PI330MC-DR. It shows the mechanical dimensions of the
housing and its mounting hole locations. The “inactive zones” are the sector without
imaging sensors.
©2000 Peripheral Imaging Corporation. Printed in USA. All rights reserved. Specifications
are subject to change without notice. Contents may not be reproduced in whole or in part without
the express prior written permission of Peripheral Imaging Corporation. Information furnished
herein is believed to be accurate and reliable. However, no responsibility is assumed by Peripheral
Imaging Corporation for its use nor for any infringement of patents or other rights granted by
implication or otherwise under any patent or patent rights of Peripheral Imaging Corporation.
PAGE 9 OF 9 - PI330MC-DR, 4/13/00