™ Peripheral Imaging Corporation PI310MC-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”) • Standard Yellow-Green light source (Other colors are available) • Compact size ~ = 15 mm x 25.6 mm x 102 mm • Low power • Light weight General Description The PI310MC-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 signal. It is based on the PI305M-A6 CIS module 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 PI310MC-DR is suitable for scanning documents with widths up to 89 mm and with resolution of 11.8 dots per millimeter. It has broad applications, but was 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. PAGE 1 of 10 PI310MC-DR Description, 7/30/99 Peripheral Imaging Corporation The background-tracking-digitizing circuits in the PI310MC-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. PI310MC-DR Module Block Diagram. The PI310MC-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 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 the analog digitizing circuit, where video pixels are converted to a digital signal and outputted from the module. See Figure 1, the block diagram of the PI310MC-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 that 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 PI310MC-DR cross section is shown in Figure 2. PAGE 2 of 10 PI310MC-DR Description, 7/30/99 Peripheral imaging Corporation DOCUMENT SURFACE GLASS WINDOW ROD LENS MODULE HOUSE LIGHT PATH D LE R BA SENSORS PCB Figure 2. PI310MC-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. It is on the top of the module with the glass window facing down and it is on the opposite side of the module. See the Mechanical Housing under Mechanical Structure. Circuit Description and Operation Figure 3 depicts 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 PI310MC-DR and derives a tracking background reference signal. This reference is then compared against the output signals from the CIS section. The resulting signal by 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. PAGE 3 of 10 PI310MC-DR Description, 7/30/99 Peripheral imaging Corporation Figure 1, PI310MC-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 CIS module produces the analog image pixel signals (video) that are proportional to the exposure on the corresponding document picture element. The video is then inputted to the tracking digitizer. In turn, the digitizer converts 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. The unmodified signal (image pixels) are applied to one 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. • VDD is on Pin 2. This is a + 5 Volts supply. PAGE 4 of 10 PI310MC-DR Description, 7/30/99 Peripheral Imaging Corporation • 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 mm µsec Note @ 2.0 MHz clock frequency Clock frequency f 2.0 MHz Bright output Digital Video >3.2 Volts Dark output Output Signal <0.8 Volts (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 adjusted for the specific application. Table 3. Recommended Operating Conditions (25 °C) Item Power Supply Input voltage at digital high Input voltage at digital low Clock frequency Clock pulse high duty cycle Symbol Vdd Vn. VLED Idd Ivn ILED Vih Vil f Min Mean 5.0 -10 Vdd-1.0 0 Max -5 24 (1) 25 10 85 Vdd-.5 25 PAGE 5 of 10 PI310MC-Dr Description, 7/30/99 Vdd 0.8 2.5 Units V V V mA mA mA V V MHz % Peripheral Imaging Corporation Table 3. (Continued) Clock pulse high duration Clock 100 (2) ns (3) Integration time Tint 0.423 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 constant 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 adjusted for the specific application. 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. tw to CP tdh tprh SP tds tdl Vanalog tsh tddl tdodl Digout FIGURE 4. Module Timing Diagram PAGE 6 of 10 PI310MC-DR Description, 7/30/99 Peripheral Imaging Corporation Table 4. Switching Parameter and Timing Symbol Definition Symbol Min. 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 Digital Signal Delay Digital Signal Off Delay Typical 0.50 Max. Units µs ns 50 % ns to tw 100 tprh 25 15 tds tdh tdl 20 20 50 ns ns ns tsh 120 ns tddl 60 ns tdodl 300 ns Table 5 Absolute Maximum Rating: Parameter Symbols Power supply voltage Input clock pulse (high level) Input clock pulse (low Units Vdd Idd Vn Ivn VLED ILED Vih Maximum Rating 10 50 -15 30 26 100 Vdd – 0.5 Vil -0.8 V Top Hop Tstg Hstg 0 to 50 10 to 85 -25 to +75 5 to 95 ºC % ºC % V mA V mA V mA V Table 6 Operating Environment Operating temperature Operating humidity Storage temperature Storage humidity PAGE 7 of 10 PI310MC-DR Description, 7/30/99 Peripheral Imaging corporation Setup and Adjustments The Clock Rate and Integration Time The following values were factory set for 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 -10 Volts +24 Volts @ 25 mA @ 10 mA @ 90 mA Adjustments General Location of Test, Adjustment and Monitor Points BACK SIDE OF THE PCB AS VIEWED ON MODULE WITH THE GLASS WINDOW FACING DOWN. R16 (Gain Adj) TV TR TVD R18 (Offset Adj) Connector VLED GLED FIGURE 5. PI310MC-DR PCB Monitor & Test Points Figure 5, PI310MC-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. Page 8 of 10 PI310MC-DR Description, 7/30/99 Peripheral imaging Corporation Offset adjust, R18, is a screw driver adjustment potentiometer that is accessed through adjustment hole as viewed in figure 5. Gain adjust, R16, 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-set to the customer’s specific application at the factory, therefore, in general will not require trimming by the user. Test point TV is probed with a scope to monitor the analog image pixel levels. 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. Analog Zero signal adjust (OFFSET ADJ) as it is shown in Figure 5. This pot is adjusted to place the dark level of the analog image pixel signal to approximately –0.9 to –0.7 Volts. Normally adjusted with intended targets. Analog Gain adjust, “GAIN”, is adjusted greater than 2.0 and less then 3.5 Volts with the CIS imaged on a standard white target similar to the standard white copy or typing paper. Page 9 of 10 PI310MC-DR Description, 7/30/99 Peripheral imaging Corporation Mechanical Structure Note: All dimensions in mm. m ne 4m zo ne zo ad e 0 d 1 ate im x o pr ap .0 er or 15 centnect e n th co Tof the o 2 10 imum ad de x ma ma 25.6 x im um ns sio en ters m Di me All Milli in 8.0 12 .7 Two sets of mounting holes are mirror imaged on both ends. Hole = 2x2 M1.8 Top Right Screw 1mm x 8 Flex cable connector 22 .0 6.8 24 .6 Readline 6.0 6.8 FIGURE 6. Mechanical Structure Figure 6 is a pictorial of the PI310MC-DR. It illustrates the mechanical dimensions of the housing and its mounting hole locations. The “dead zones” represent the package extremes that are outside the image sensor active area. Page 10 of 10 PI310MC-DR Description, 7/30/99 ©1999 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.