Near-Field Touch Interface Using Time-of-Flight Camera

2016 ◽  
Vol 28 (5) ◽  
pp. 759-775 ◽  
Author(s):  
Lixing Zhang ◽  
◽  
Takafumi Matsumaru ◽  
Keyword(s):  
Near Field ◽  
Time Of Flight ◽  
Image Sensor ◽  
Sensor System ◽  
Robust Detection ◽  
3 Dimensional ◽  
Position Detection ◽  
Small Standard Error ◽  
Working Distance ◽  
Touch Interfaces

[abstFig src='/00280005/20.jpg' width='300' text='Near-field touch interface system, NFTIS' ] The purpose of this study is to realize a near-field touch interface that is compact, flexible, and highly accurate. We applied a 3-dimensional image sensor (time-of-flight camera) to achieve the basic functions of conventional touch interfaces, such as clicking, dragging, and sliding, and we designed a complete projector-sensor system. Unlike conventional touch interfaces, such as those on tablet PCs, the system can sense the 3-dimensional positions of fingertips and 3-dimensional directions of fingers. Moreover, it does not require a real touch screen but instead utilizes a mobile projector for display. Nonetheless, the system is compact, with a working distance of as short as around 30 cm. Our methods solve the shadow and reflection problems of the time-of-flight camera and can provide robust detection results. Tests have shown that our approach has a high success rate (98.4%) on touch/hover detection and a small standard error (2.21 mm) on position detection on average for different participants, which is the best performance we have achieved. Some applications, such as the virtual keyboard and virtual joystick, are also realized based on the proposed projector-sensor system.

Accuracy Performance of a Time-of-Flight CMOS Range Image Sensor System

2009 ◽  
Vol 58 (5) ◽  
pp. 1563-1570 ◽  
Author(s):  
F. Leonardi ◽  
D. Covi ◽  
D. Petri ◽  
D. Stoppa
Keyword(s):  
Time Of Flight ◽  
Image Sensor ◽  
Sensor System ◽  
Range Image ◽  
Accuracy Performance

A Two-Tap Indirect Time-of-Flight CMOS Image Sensor With Pump Gate Modulator for Low-Power Applications

2021 ◽  
pp. 1-7
Author(s):  
Bing Zhang ◽  
Congzhen Hu ◽  
Junhua Lai ◽  
Youze Xin ◽  
Zhuoqi Guo ◽  
...  
Keyword(s):  
Low Power ◽  
Time Of Flight ◽  
Cmos Image Sensor ◽  
Image Sensor

A Time-of-Flight CMOS Range Image Sensor Using 4-Tap Output Pixels with Lateral-Electric-Field Control

2016 ◽  
Vol 2016 (12) ◽  
pp. 1-6 ◽  
Author(s):  
Taichi KASUGAI ◽  
Sang-Man HAN ◽  
Hanh TRANG ◽  
Taishi TAKASAWA ◽  
Satoshi AOYAMA ◽  
...  
Keyword(s):  
Electric Field ◽  
Time Of Flight ◽  
Image Sensor ◽  
Range Image ◽  
Lateral Electric Field ◽  
Field Control

A 64 × 64 SPAD-Based Indirect Time-of-Flight Image Sensor With 2-Tap Analog Pulse Counters

2021 ◽  
Vol 56 (10) ◽  
pp. 2956-2967
Author(s):  
Byungchoul Park ◽  
Injun Park ◽  
Chanmin Park ◽  
Woojun Choi ◽  
Yoondeok Na ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Image Sensor

scholarly journals Magnetic Positioning Technique Integrated with Near-Field Communication for Wireless EV Charging

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1081 ◽  
Author(s):  
Zhongnan Qian ◽  
Rui Yan ◽  
Zeqian Cheng ◽  
Jiande Wu ◽  
Xiangning He
Keyword(s):  
Relative Position ◽  
Data Transmission ◽  
Power Efficiency ◽  
Near Field ◽  
Three Dimensional ◽  
Secondary Coil ◽  
Power Transfer ◽  
Electric Vehicle Charging ◽  
Position Detection ◽  
Positioning Method

For wireless electric vehicle charging, the relative position of the primary and secondary coils has significant impacts on the transferred power, efficiency and leakage magnetic flux. In this paper, a magnetic positioning method using simultaneous power and data transmission (SWPDT) is proposed for power coil alignment. Four signal coils are installed on the primary coil to detect the secondary coil position. By measuring the positioning signal amplitudes from the four signal coils, the power coil relative position can be obtained. Moreover, all the communication needed in the positioning process can be satisfied well by SWPDT technology, and no extra radio frequency (RF) communication hardware is needed. The proposed positioning method can work properly both in power transfer online condition and in power transfer offline condition. Thus, a highly integrated wireless charging system is achieved, which features simultaneous power transfer, data transmission and position detection. A positioning experimental setup is built to verify the proposed method. The experimental results demonstrate that the positioning resolution can be maintained no lower than 1 cm in a 1060 mm × 900 mm elliptical region for a pair of 510 mm × 410 mm rectangular power coils. The three-dimensional positioning accuracy achieves up to 1 cm.

scholarly journals Numerical Prediction of Background Buildup of Salinity Due to Desalination Brine Discharges into the Northern Arabian Gulf

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2284 ◽  
Author(s):  
Aaron C. Chow ◽  
Wilbert Verbruggen ◽  
Robin Morelissen ◽  
Yousef Al-Osairi ◽  
Poornima Ponnumani ◽  
...  
Keyword(s):  
Near Field ◽  
Regional Scale ◽  
Arabian Gulf ◽  
Potential Effect ◽  
Horizontal Resolution ◽  
Point Of View ◽  
Far Field ◽  
Exchange Flow ◽  
3 Dimensional ◽  
Desalination Plants

Brine discharges from desalination plants into low-flushing water bodies are challenging from the point of view of dilution, because of the possibility of background buildup effects that decrease the overall achievable dilution. To illustrate the background buildup effect, this paper uses the Arabian (Persian) Gulf, a shallow, reverse tidal estuary with only one outlet available for exchange flow. While desalination does not significantly affect the long-term average Gulf-wide salinity, due to the mitigating effect of the Indian Ocean Surface Water inflow, its resulting elevated salinities, as well as elevated concentrations of possible contaminants (such as heavy metals and organophosphates), can affect marine environments on a local and regional scale. To analyze the potential effect of background salinity buildup on dilutions achievable from discharge locations in the northern Gulf, a 3-dimensional hydrodynamic model (Delft3D) was used to simulate brine discharges from a single hypothetical source location along the Kuwaiti shoreline, about 900 km from the Strait of Hormuz. Using nested grids with a horizontal resolution, comparable to a local tidal excursion (250 m), far field dilutions of about 28 were computed for this discharge location. With this far field dilution, to achieve a total dilution of 20, the near field dilution (achievable using a submerged diffuser) would need to be increased to approximately 70. Conversely, the background build-up means that a near field dilution of 20 yields a total dilution of only about 12.

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