EBOOK - Smart CMOS Image sensors and applications (Jun Ohta) | Cộng đồng Kỹ thuật cơ điện Việt Nam EBOOKBKMT

EBOOK - Smart CMOS Image sensors and applications (Optical Science and Engineering) - Jun Ohta.

EBOOK - Cảm biến hình ảnh thông minh CMOS và ứng dụng (Jun Ohta) - 267 Trang.

Image sensors have recently attracted renewed interest for use in digital cameras, mobile phone cameras, handy camcoders, cameras in automobiles, and other devices.
For these applications, CMOS image sensors are widely used because they feature on-chip integration of the signal processing circuitry. CMOS image sensors for such specific purposes are sometimes called smart CMOS image sensors, vision chips,computational image sensors, etc.

Smart CMOS Image Sensors & Applications focuses on smart functions implemented in CMOS image sensors and their applications. Some sensors have already been commercialized, whereas some have only been proposed; the field of smart CMOS image sensors is active and generating new types of sensors. In this book I have endeavored to gather references related to smart CMOS image sensors and their applications; however, the field is so vast that it is likely that some topics are not described. Furthermore, the progress in the field is so rapid that some topics will develop as the book is being written. However, I believe the essentials of smart CMOS image sensors are sufficiently covered and that this book is therefore useful for graduate school students and engineers entering the field.

CONTENTS.

1 Introduction 1
1.1 Ageneraloverview ......................... 1
1.2 BriefhistoryofCMOSimagesensors ............... 2
1.3 BriefhistoryofsmartCMOSimagesensors ............ 5
1.4 Organization of the book . ..................... 8
2 Fundamentals of CMOS image sensors 11
2.1 Introduction . . . . ......................... 11
2.2 Fundamentals of photodetection . ................. 12
2.2.1 Absorptioncoefficient ................... 12
2.2.2 Behaviorofminoritycarriers................ 13
2.2.3 Sensitivityandquantumefficiency............. 15
2.3 PhotodetectorsforsmartCMOSimagesensors .......... 17
2.3.1 pn-junction photodiode . . ................. 18
2.3.2 Photogate.......................... 26
2.3.3 Phototransistor ....................... 26
2.3.4 Avalanche photodiode . . ................. 27
2.3.5 Photoconductive detector . ................. 27
2.4 AccumulationmodeinPDs ..................... 29
2.4.1 Potential change in accumulation mode . . . . ...... 30
2.4.2 Potentialdescription .................... 30
2.4.3 Behavior of photo-generated carriers in PD . . ...... 32
2.5 Basicpixelstructures ........................ 36
2.5.1 Passivepixelsensor..................... 36
2.5.2 Activepixelsensor,3T-APS ................ 38
2.5.3 Activepixelsensor,4T-APS ................ 40
2.6 Sensorperipherals .......................... 42
2.6.1 Addressing ......................... 42
2.6.2 Readout circuits . . ..................... 45
2.6.3 Analog-to-digitalconverters ................ 46
2.7 Basicsensorcharacteristics ..................... 48
2.7.1 Noise ............................ 48
2.7.2 Dynamicrange ....................... 51
2.7.3 Speed............................ 51
2.8 Color................................. 51
2.9 Pixelsharing............................. 53
2.10 Comparisonbetweenpixelarchitecture............... 55
2.11 ComparisonwithCCDs ....................... 55
3 Smart functions and materials 59
3.1 Introduction . . . . ......................... 59
3.2 Pixelstructure ............................ 60
3.2.1 Currentmode........................ 60
3.2.2 Logsensor ......................... 62
3.3 Analogoperation .......................... 64
3.3.1 Winner-take-all....................... 64
3.3.2 Projection.......................... 65
3.3.3 Resistivenetwork...................... 65
3.4 Pulse modulation . ......................... 66
3.4.1 Pulse width modulation . . ................. 68
3.4.2 Pulse frequency modulation . . .............. 70
3.5 Digitalprocessing .......................... 78
3.6 Materials other than silicon ..................... 79
3.6.1 Silicon-on-insulator..................... 79
3.6.2 Extendingthedetectionwavelength ............ 83
3.7 Structures other than standard CMOS technologies . . ...... 85
3.7.1 3Dintegration........................ 85
3.7.2 Integration with light emitters . . ............. 86
3.7.3 Color realization using nonstandard structures . ...... 88
4 Smart imaging 93
4.1 Introduction . . . . ......................... 93
4.2 Lowlightimaging .......................... 94
4.2.1 Activeresetforlowlightimaging ............. 96
4.2.2 PFMforlowlightimaging................. 96
4.2.3 DifferentialAPS ...................... 97
4.2.4 Geiger mode APD for a smart CMOS image sensor . . . . 97
4.3 Highspeed.............................. 99
4.3.1 Globalshutter........................ 99
4.4 Wide dynamic range......................... 100
4.4.1 Principle of wide dynamic range . ............. 100
4.4.2 Dualsensitivity....................... 101
4.4.3 Nonlinear response ..................... 102
4.4.4 Multiple sampling ..................... 105
4.4.5 Saturationdetection..................... 107
4.4.6 Diffusivebrightness .................... 108
4.5 Demodulation . . . ......................... 108
4.5.1 Principles of demodulation................. 108
4.5.2 Correlation ......................... 109
4.5.3 Method of two accumulation regions . . . . . ....... 111
4.6 Three-dimensionalrangefinder ................... 116
Table of Contents xvii
4.6.1 Timeofflight........................ 116
4.6.2 Triangulation . . . ..................... 121
4.6.3 Depthkey.......................... 123
4.7 Targettracking............................ 123
4.7.1 Maximumdetectionfortargettracking........... 124
4.7.2 Projectionfortargettracking................ 124
4.7.3 Resistive network and other analog processing for target tracking..... 125
4.7.4 Digitalprocessingfortargettracking............ 125
4.8 Dedicatedarrangementofpixelandoptics ............. 129
4.8.1 Non-orthogonal arrangement . . . ............. 129
4.8.2 Dedicatedoptics ...................... 132

5 Applications 137

5.1 Introduction . . . . ......................... 137

5.2 Informationandcommunicationapplications............ 137

5.2.1 OpticalIDtag........................ 138

5.2.2 Opticalwirelesscommunication.............. 144

5.3 Biotechnology applications ..................... 151

5.3.1 Smart CMOS image sensor with multi-modal functions . . 152

5.3.2 Potential imaging combining MEMS technology . . . . . 155

5.3.3 Smart CMOS sensor for optical and electrochemical imaging......

5.3.4 Fluorescencedetection................... 159

5.4 Medicalapplications ........................ 165

5.4.1 Capsule endoscope ..................... 165