論文目次 |
Table of Contents
中文摘要……………………………………………………………………………..……I
英文摘要……………………………………………………………………………..……II
誌謝………………………………………………………………………………….……III
Table of Content………………………………….………………………………….……IV
List of figures………………………………….…………………………………………VII
List of tables…………………………………………..………………………………….X
Explanation of Symbols……………………………….………………………………....XI
Chapter 1 Overview of Thin Film Transistor Liquid Crystal Display………………1
1.1 Introduction to TFT-LCD System……………………………………………………1
1.2 Current status of TFT-LCD…………………………………………………………..3
1.2.1 The Status of Back Lighting Module of TFT LCD System…………..………3
1.2.2 The Status of TFT LCD Panel Inspection …………………………..………..5
1.3 Research Motivation and Contributions……………………………………..………6
1.3.1 Research of the LED Backlight Module by a Light Guide Component……6
1.3.2 Research of the Mura Inspection of TFT LCD Panel……………………..…7
1.4 Dissertation Outline……………………………………………………….………...8
Chapter 2 LED Backlight Module by a Lightguide- Component…………………..9
2.1 Abstract……………………………………………………………………………..9
2.2 Introduction…………………………………………………………………………10
2.3 Material and Method…………………………………………………….………….12
2.3.1 Preliminary Design………………………………………………………….12
2.3.1.1 Preliminary Design of the LED Backlight module…………………..12
2.3.1.2 Evaluation of the Simulated Results of the Backlight Module……….14
2.3.1.3 Thermal Design of the LED Backlight module……………….……..15
2.3.1.4 Preliminary Simulation of the Backlight Module……………….…..16
2.3.2 Advanced Design…………………………………………………….……..26
2.3.3 Measurement and Methodlogy……………………………………………..30
2.4 Results……………………………………………………………………………..32
2.5 Summary…………………………………………………………………………..34
Chapter 3 Detection of Gap Mura in TFT LCDs by the Interference
Pattern Method…………………………………………………….…….36
3.1 Abstract…………………………………………………………………….……..36
3.2 Introduction………………………………………………………………….……37
3.3 Materials and Methods……………………………………………………………42
3.3.1 Theory-Fringes of equal thickness…………………………………….…..42
3.3.2 Experimental Equipment………………………………………………….46
3.3.3 Image Processing Method…………………………………………..…….47
3.3.4 Experimental Methodology of Panel Inspection…………….…………..48
3.3.4.1 Definition of Cross Points……………………………….………49
3.3.4.2 Definition of Binary Classification Method……………….…….52
3.3.5 Neural Network Classification System ...………………………………54
3.3.5.1 Definition of the parameters……………………………….……54
3.3.5.2 Experimental Procedure of Neural Network Classification….…60
3.4 Results…………………………………………………………………………64
3.5 Summary………………………………………………………………………71
Chapter 4 Conclusion and Future Work………………………………………..73
4.1 Conclusion……………………………………………………………………..73
4.2 Future Work……………………………………………………………………74
Reference………………………………………………………………………….76
List of figures
Fig. 1.1. Schematic of a basic element of a LCD system………………………….……….1
Fig. 2.1. Structure of the direct illumination-type LED Backlight module……………...11
Fig. 2.2. Secondary lightguide component model……………………………………….12
Fig. 2.3. Illustration of the backlight module with four secondary
Lightguide components………………………………………………………...13
Fig. 2.4. Positions of points P1- P16……………………………………………………..15
Fig. 2.5. Simulation results for the flat reflector…………………………………………16
Fig. 2.6. Illustration of ray tracing with total reflection in the backlight module………..17
Fig. 2.7. Schematic representation of ray tracing with a tilted reflector…………………17
Fig. 2.8. Diagram of the secondary lightguide component…………………………….18
Fig. 2.9. Right-hand spherical coordinates……………………………………………….18
Fig. 2.10. Relation of P0, P1, P2 and P’……………………………………………………19
Fig.2.11. Illustration of ray tracing with total reflecting in the backlight module…………22
Fig.2.12. Schematic representation of the ray tracing with a tilted reflector.……….….….22
Fig. 2.13. Structures and locations of the Triangle Cylinder Structured Array
(units: mm)……………………………………………………………………..23
Fig. 2.14. Schematic representation of the six sections (sections N1-N6)…………..…….23
Fig. 2.15. Triangle Cylinder Structured Array simulation results:
(a) N (5,10,5,6,6,6); (b) N (5,10,5,6,8,6); (c) N (5,10,5,8,8,8)……………..….25
Fig. 2.16. Triangle Cylinder Structured Array polar candela plot: Blue
line-N (5,10,5,6,6,6); Red line-N (5,10,5,6,8,6); Black line-N (5,10,5,8,8,8)....26
Fig. 2.17. Structures and locations of the Tetrahedron Reflector Structured
Array (units: mm)………………………………………………………………27
Fig. 2.18. Tetrahedron Reflector Structured Array simulation results:
(a) N (5,10,5,6,6,6); (b) N (5,10,5,6,8,6); (c) N (5,10,5,8,8,8)………….………29
Fig. 2.19. Tetrahedron Reflector Structure Array polar candela plot: Blue
line-N (5,10,5,6,6,6); Red line-N (5,10,5,6,8,6); Black line-N (5,10,5,8,8,8)…29
Fig.2.20. Test platform for the backlight module………………………………………….30
Fig. 2.21. Simulation results of the uniformity ratio………………………………………33
Fig. 2.22. Simulation results of the angle of the luminous intensity………………………34
Fig. 3.1. Examples of mura in TFT LCDs…………………………………………………38
Fig. 3.2 Interference patterns observed in a 7 inch TFT LCD panel without Liquid
Crystal under a sodium lamp……………………………………………………..40
Fig. 3.3. Different sealant problems that can cause mura defects…………………………41
Fig. 3.4. Different sealant problems which can cause mura………………………………41
Fig. 3.5. Normal interference patterns of a TFT LCD under sodium light………………..43
Fig. 3.6. Abnormal interference patterns of a TFT LCD under sodium light……………..44
Fig. 3.7. Light path of point source S through planar parallel plates……………….…….44
Fig. 3.8. Schematic representation of the interference pattern analysis system.
An image catcher is used to capture the panel image.…………………………..47
Fig. 3.9. Image processing flow chart…………………………………………………….48
Fig. 3.10. Panel judging flow chart……………………………………………………….49
Fig. 3.11. (a) 5 cross points on the top and 5 cross points on the left side. (b) 7 cross
points on the top. (c) 35 cross points in the central area………………..……..52
Fig. 3.12. Neural Network configuration built with one input layer, one hidden layer,
and one output layer.............................................................................................56
Fig. 3.13. 16 panels prepared for this experiment, 10 panels prepared for learning and
training, and 6 panels are for testing…………………………………………..60
Fig. 3.14. Set of good panels without mura. (a) section No. 34, (b) section No. 180……61
Fig. 3.15. Set of bad panels with mura. (a) section No. 122, dense image
(b) section No. 42, star shape image……………………………….…………..62.
Fig. 3.16. The judgement results of each sections on the LCD panels…………………..63
Fig. 3.17 Test results based on two different criteria: (a) Criterion 1:
threshold = 130 points; (b) Criterion 2: threshold = 120 points………………..68
List of tables
Table 2.1 The relation of α,β, l , m , n and θ2……………………………………………21
Table 2.2 Simulated Results of the Triangle Cylinder Structure Array and Tetrahedron
Reflector Structure Array………………………….……….…………………29
Table 2.3 Candela Plot Results of The Triangle Cylinder Structure Array and
Tetrahedron Reflector Structure Array…………….……….…………………29
Table 2.4 Measurement Result of The R.S.West’s Work and our design (Original
design and Advance design with Triangle Cylinder Array)………………...…31
Table 3.1 The features of the interference fringes…………………………….……….. 59
Table 3.2 Definition of output vectors and mura status defects………………..……….60
Table 3.3 Cross Points of 15 Panels………………………………………….…………64
Table 3.4 Compare Results of 15 Panels…………………………………….………….65
Table 3.5 Statistical Results for A Binary Classification Test………………….……….66
Table 3.6 Statistical Results When Acceptability Criterion=130 Points………….…….66
Table 3.7 Statistical Results When Acceptability Criterion=120 Points………….…….67
Table 3.8 Training data for input and output vectors…………………….……………..70
Table 3.9 The result of the test set………………………………………………………70 |
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