Touchless Interface Resonant Cavity Beamforming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of ultrasonic sensors into electronic devices for touchless gesture recognition poses a challenge due to the need for multiple transducers, which complicates the design and increases vulnerability to damage and moisture ingress, while also conflicting with the aesthetic goal of a sleek, minimalist surface.
Innovation Solution
The use of resonant cavities behind the outer surface, which provide a distinctive echoic signature to determine the direction of ultrasonic signals or reflections, allowing for beamforming without a λ/2 spaced array of transducers, reducing material and processing costs, and enabling simpler power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple ultrasonic transducers are integrated into the device for touchless gesture recognition, then gesture recognition capability is improved, but device complexity and vulnerability to damage increase
Solution Approach 1:
The patent combines multiple ultrasonic transducers into a single integrated unit that can perform both transmission and reception functions. This merging approach maintains the capability for touchless gesture recognition while reducing the number of separate components, thereby decreasing device complexity and potential vulnerability points.
Solution Approach 2:
The integrated transducer unit is designed to perform multiple functions - both transmitting ultrasonic signals and receiving reflected signals for gesture detection. This multi-functionality eliminates the need for separate transmitter and receiver components, reducing overall device complexity while maintaining full gesture recognition capability.
2Measurement precision
If multiple holes are provided in the front surface for transducer access, then signal reception is improved, but aesthetic appearance and protection against damage deteriorate
Solution Approach 1:
The patent employs a thin film or membrane structure that can vibrate in response to ultrasonic signals while maintaining a continuous, smooth front surface appearance. This flexible film allows signal reception functionality without requiring visible holes, thus preserving aesthetic appearance while enabling adequate signal reception.
Solution Approach 2:
The thin film acts as an intermediary between the external acoustic environment and the internal transducer components. It transmits acoustic signals to the transducers while blocking direct visual access to the components behind, thereby maintaining aesthetic appearance while enabling signal reception.
3Ease of manufacture
If multiple holes are provided in the front surface, then transducer access is improved, but vulnerability to moisture and dust ingress increases
Solution Approach 1:
The thin film structure provides a protective barrier that seals the front surface while allowing acoustic signal transmission. This eliminates open holes that would permit moisture and dust ingress, protecting internal components while maintaining manufacturing accessibility through alternative means.
Solution Approach 2:
The thin film serves as a sacrificial protective element that can be easily replaced if damaged, providing a simple and cost-effective solution to prevent moisture and dust ingress without requiring complex sealing mechanisms around multiple holes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for effective touchless gesture recognition without compromising the device's design aesthetics, reducing material costs and power consumption, and enhancing signal processing efficiency by using fewer transducers and maintaining a continuous surface.
Implementation Method 1
The dimensions of the cavity are such that it has a resonant frequency within the band of the ultrasonic signals
Implementation Method 2
receives the echoes from an input object in front of the device, typically the user's hand, using a set of sensing receivers
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An electronic device having a touchless user interface for providing at least one input to the device, said touchless user interface comprising at least one ultrasound transmitter arrangement 16 arranged to transmit ultrasonic signals and at least one ultrasound receiver arrangement 18 arranged to receive reflections of said ultrasonic signals from an input object 14, wherein the device further comprises a substantially continuous outer surface portion 22, wherein said outer surface portion 22 comprises at least one localised zone 30' having a greater compliance for moving in response to impingement by said ultrasonic signals or reflections such that said localised zone 30' forms part of said transmitter arrangement 16 and/or said receiver arrangement 18.