Differential Signal-Amplitude-Modulated Multi-Beam Remote Optical Touch Based on Grating Antenna.

Area of Science:

• Optoelectronics
• Human-Computer Interaction
• Sensor Technology

Background:

• Large screens exceed human physical touch limitations, necessitating remote control solutions.
• Existing remote control methods like inertial gyroscopes and camera-based gesture recognition have accuracy and range limitations.
• Grating antenna light-trapping technology presents a promising solution for multipoint inputs if ghost point issues are resolved.

Purpose of the Study:

• To propose and verify a differential amplitude modulation scheme for grating antenna-based multi-beam optical touch.
• To enable accurate recognition and differentiation of multiple incidence points on large displays.
• To provide a practical remote multi-point touch solution overcoming current technological barriers.

Main Methods:

• A differential amplitude modulation scheme was developed, coding incident beam amplitudes with distinct pulse widths.
• Grating antennas captured incident beams, which were then converted to electrical currents by aligned detector arrays.
• The system was tested on an 18-inch screen to evaluate performance metrics.

Main Results:

• The proposed scheme successfully differentiated individual incident beams, enabling multipoint recognition.
• Achieved two-point optical touch with position accuracy error under 3 mm.
• Demonstrated a response time of less than 7 ms at a 10 kHz modulation frequency.

Conclusions:

• The differential amplitude modulation scheme provides a practical method for remote multi-point optical touch.
• This technology overcomes limitations of existing remote control systems for large displays.
• Enables more intuitive and accurate remote interaction, mimicking natural pointing behaviors.