Chapter 44-16Functions of the image processing system are summarized below.T-4-10The reader controller PCB is used to process images on a line-by-line basis. Its major functions are as follows:1)Analog image processing- CMOS sensor drive- CMOS sensor output gain correction and offset correction- CMOS sensor output A/D conversion2)Digital image processing- Shading correctionF-4-304.3.6.2 CMOS Sensor Drive 0017-2637iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018iThe CMOS sensor used in this machine is a 1-line linear image sensor consisting of 7488 photocells. After completion of photoelectric conversion in the light-receiving block, the signals are output to the AP circuit in the reader controller PCB in parallel for each channel (total four channels) of the CMOS sensor array.F-4-314.3.6.3 CMOS Sensor Output Gain Correction and Offset Correction 0017-2638iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018iThe analog video signals output from the CMOS sensor are corrected so that they will have a specific gain level (gain correction), and the output voltages generatedin the absence of incident light are also corrected so that they it will have a specific offset level (offset correction).4.3.6.4 CMOS Sensor Output A/D Conversion 0017-2639iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018iAfter completion of the above corrections, the analog video signals are converted to digital signals corresponding to individual pixel voltage levels by the A/Dconverter.4.3.6.5 Shading Correction (Outline) 0017-2640iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018i- Reader controller PCB CMOS sensor drive, analog image processing, A/Dconversion, and shading correctionTargetvalueCMOS sensor (1 line)Analog image signalAnalog imageprocessing- Gain correction- Offset correctionA/DconversionCMOS sensordrive controlCMOS sensorcontrol signalGaincorrectiondataDigitalimagesignalIC110Digital imagesignal8Reader controller PCBContact image sensor (CIS)J309RAMShading correctionIC2SerialcommunicationI/FCMOS sensor 1CMOS sensor 4 CMOS sensor 3HL L HH L HL H H LoutputLight receiving block
