3D Time-of-flight distance measurement with custom - Universität ...

More documents

Recommendations

Info

DEMODULATION PIXELS IN CMOS/CCD 133 potential potential INTG PGL PGM PGR 10V 0V 5V 0V 5V 0V 0V 5V 0V 5V 5V 4V 4V 0V 5V 0V PGM=4V potential potential INTG PGL PGM PGR 10V 0V 5V 0V 5V 0V PGM=0V PGM=0V PGM=4V BCCD SCCD Figure 5.18 Influence of the PGM voltage on the demodulation contrast for BCCD and SCCD realizations. Saturation velocity We know that the velocity of charge carriers increases linearly with the applied electrical field only for small electrical fields. For higher fields the velocity reaches a saturation value (10 7 cm/s in silicon). Now we want to examine if the saturation velocity is already reached for a potential difference of 10 V between two adjacent gates. Estimation: Gate length: 6 µm Potential difference: 10 V Electrical field: 1.7⋅10 4 V/cm Doping concentration (BCCD): 4⋅10 16 cm -3 . Electron mobility @ doping concentration 10 3 cm 2 /Vs Saturation velocity vs 10 7 cm/s µ ⋅E Drift velocity: v = µ ⋅E 1+ v 0.63 ⋅ 10 7 cm/s = 0.63 ⋅ vs s
134 CHAPTER 5 We see that even for 10 V the saturation velocity is not yet reached. The results we presented (increase in demodulation contrast for increased PGL / PGR voltage) are reasonable because an increase in electrical field still causes an increased drift velocity and hence faster response of charge carriers to the electrical field, leading to a better demodulation contrast at high modulation frequencies. 5.2.4 Influence of optical power and integration time @ 20MHz We discussed in Section 3.2 that the charge transfer efficiency of CCDs strongly depends on the number of charge carriers that are contained in the charge packet to transport (c.f. Figure 3.20). Therefore we expect the optical power, i.e. how many photoelectrons are generated (and hence have to be transported) per unit time, to have a noticeable influence on the demodulation contrast. This is investigated in the current section. In order to measure the influence of the number of generated photoelectrons per unit time on the contrast, two parameters are changed: (1) the optical power and (2) the integration times. For a good reproducibility of the measurements we keep the output power of the LED constant and use neutral density filters (ND) to attenuate the power on the pixel. This has the advantage that the LED can be operated with the same mean current (50 mA) for all measurements. (Because of a currentdependent operating temperature, the LED changes its dynamic characteristics for different control currents). For each integration time we chose a different spot size (by adjusting the distance of the microscope’s objective to the sensor chip), the exact parameters are summarized in MCD05 in the appendix. We carry out measurements of the demodulation contrast for 4 different optical power conditions (1) without ND filter, (2) with 27% ND filter (3) with 8% ND filter and (4) with both intensity filters (2% attenuation). Since the total optical power and the size of the light spot are measured, we can recalculate the optical power on the light sensitive area of each pixel. The dark current is measured separately and subtracted from the measured values before calculating the demodulation contrast. These measurements have only been performed for the surface-channel realization (SCCD); the results are shown in Figure 5.19 and Figure 5.20.
Page 1 and 2:
3D Time-of-flight distance measurem
Page 3 and 4:
To my parents
Page 5 and 6:
Meinen Eltern
Page 7 and 8:
II 4. Power budget and resolution l
Page 10 and 11:
Abstract Since we are living in a t
Page 12:
centimeter accuracy. With the singl
Page 15 and 16:
X Eine elegantere Methode zur Entfe
Page 18 and 19:
INTRODUCTION 1 1. Introduction One
Page 20 and 21:
INTRODUCTION 3 light source observe
Page 22 and 23:
INTRODUCTION 5 Propagation time, ho
Page 24 and 25:
INTRODUCTION 7 Chapter 3 gives a sh
Page 26 and 27:
OPTICAL TOF RANGE MEASUREMENT 9 2.
Page 28 and 29:
Page 30 and 31:
OPTICAL TOF RANGE MEASUREMENT 13 pr
Page 32 and 33:
OPTICAL TOF RANGE MEASUREMENT 15 hi
Page 34 and 35:
OPTICAL TOF RANGE MEASUREMENT 17 Pu
Page 36 and 37:
OPTICAL TOF RANGE MEASUREMENT 19 Ad
Page 38 and 39:
OPTICAL TOF RANGE MEASUREMENT 21 pr
Page 40 and 41:
OPTICAL TOF RANGE MEASUREMENT 23 wh
Page 42 and 43:
OPTICAL TOF RANGE MEASUREMENT 25 δ
Page 44 and 45:
OPTICAL TOF RANGE MEASUREMENT 27 c(
Page 46 and 47:
OPTICAL TOF RANGE MEASUREMENT 29 A
Page 48 and 49:
OPTICAL TOF RANGE MEASUREMENT 31 ph
Page 50 and 51:
OPTICAL TOF RANGE MEASUREMENT 33 Ts
Page 52 and 53:
OPTICAL TOF RANGE MEASUREMENT 35 f1
Page 54 and 55:
OPTICAL TOF RANGE MEASUREMENT 37 an
Page 56 and 57:
OPTICAL TOF RANGE MEASUREMENT 39 in
Page 58 and 59:
OPTICAL TOF RANGE MEASUREMENT 41 Ss
Page 60 and 61:
OPTICAL TOF RANGE MEASUREMENT 43 Fr
Page 62 and 63:
OPTICAL TOF RANGE MEASUREMENT 45 1
Page 64:
Page 67 and 68:
50 CHAPTER 3 the smearing effect, r
Page 69 and 70:
52 CHAPTER 3 3.1 Silicon properties
Page 71 and 72:
54 CHAPTER 3 (a) Figure 3.3 Optical
Page 73 and 74:
56 CHAPTER 3 Quantum efficiency in
Page 75 and 76:
58 CHAPTER 3 The different operatio
Page 77 and 78:
60 CHAPTER 3 (a) (b) Depletion widt
Page 79 and 80:
62 CHAPTER 3 Very special processes
Page 81 and 82:
64 CHAPTER 3 1 kT Dn = ⋅ vth ⋅
Page 83 and 84:
66 CHAPTER 3 The proportionality fa
Page 85 and 86:
68 CHAPTER 3 difference of only 1 V
Page 87 and 88:
70 CHAPTER 3 Flicker noise is cause
Page 89 and 90:
72 CHAPTER 3 A s = sf ⋅ q C ⎡ V
Page 91 and 92:
74 CHAPTER 3 amount of the charge p
Page 93 and 94:
76 CHAPTER 3 substrate (Equation 3.
Page 95 and 96:
78 CHAPTER 3 charge carriers the CT
Page 97 and 98:
80 CHAPTER 3 without causing short
Page 99 and 100: 82 CHAPTER 3 Over an address decode
Page 101 and 102: 84 CHAPTER 3 Orbit’s 2.0µm CMOS/
Page 103 and 104: 86 CHAPTER 4 Figure 4.1 P lens Lamb
Page 105 and 106: 88 CHAPTER 4 Required optical power
Page 107 and 108: 90 CHAPTER 4 4.2 Noise limitation o
Page 109 and 110: 92 CHAPTER 4 number of pseudo-backg
Page 111 and 112: 94 CHAPTER 4 Cmod = 1 QE(λ) = 0.65
Page 113 and 114: 96 CHAPTER 4 Range accuracy (std) i
Page 116 and 117: DEMODULATION PIXELS IN CMOS/CCD 99
Page 168 and 169: IMAGING TOF RANGE CAMERAS 151 6. Im
Page 170 and 171: IMAGING TOF RANGE CAMERAS 153 contr
Page 172 and 173: IMAGING TOF RANGE CAMERAS 155 6.1.2
Page 174 and 175: IMAGING TOF RANGE CAMERAS 157 gate
Page 176 and 177: IMAGING TOF RANGE CAMERAS 159 6.2 2
Page 178 and 179: IMAGING TOF RANGE CAMERAS 161 n+ di
Page 180 and 181: IMAGING TOF RANGE CAMERAS 163 pixel
Page 182 and 183: IMAGING TOF RANGE CAMERAS 165 Power
Page 184 and 185: IMAGING TOF RANGE CAMERAS 167 Delay
Page 186 and 187: IMAGING TOF RANGE CAMERAS 169 6.3 3
Page 188 and 189: IMAGING TOF RANGE CAMERAS 171 Gate
Page 190 and 191: IMAGING TOF RANGE CAMERAS 173 Bound
Page 192 and 193: IMAGING TOF RANGE CAMERAS 175 Figur
Page 194 and 195: IMAGING TOF RANGE CAMERAS 177 Final
Page 196 and 197: IMAGING TOF RANGE CAMERAS 179 #5 #6
Page 198 and 199: SUMMARY AND PERSPECTIVE 181 7. Summ
Page 200 and 201:
SUMMARY AND PERSPECTIVE 183 into th
Page 202:
SUMMARY AND PERSPECTIVE 185 or phas
Page 205 and 206:
188 CHAPTER 8 8.2 Typical parameter
Page 207 and 208:
190 CHAPTER 8 Spectral luminous int
Page 209 and 210:
192 CHAPTER 8 MCD03S: Conditions SC
Page 211 and 212:
194 CHAPTER 8 MCD06S: Measurement c
Page 213 and 214:
196 [BRK] Brockhaus, “Naturwissen
Page 215 and 216:
198 [KAI] I. Kaisto, et al., “Opt
Page 217 and 218:
200 [SP1] T. Spirig et al., “The
Page 220 and 221:
ACKNOWLEDGMENTS 203 Acknowledgments
Page 222:
206 Publication list 1. R. Lange, P
show all

3D Time-of-flight distance measurement with custom - Universität ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?