Self-Mixing Interferometry Sensor for 3D Gesture Input
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional user input devices in electronic devices, such as buttons and touch screens, require physical contact and are limited to two-dimensional input, failing to detect distance or gestures, which adds weight, size, and power consumption, and restricts input versatility.
Innovation Solution
The use of a self-mixing interferometry sensor that projects a light beam onto an input surface, detecting reflections to generate a self-mixing interferometry signal, allowing for the determination of distances, displacements, velocity, and motion of user inputs like fingers or styluses, enabling three-dimensional input detection and interaction with projected images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional user input devices (buttons, touch screens) are integrated into electronic devices, then user input functionality is provided, but device weight, size, and power consumption increase
Solution Approach 1:
The patent extracts the user input detection function from physical hardware components and relocates it to an optical sensing system using a light source and photodetector. This extraction eliminates the need for heavy mechanical buttons and touch screen assemblies, thereby reducing device weight while maintaining input functionality through optical detection of user interactions.
Solution Approach 2:
The patent replaces mechanical input devices (buttons, physical switches) with an optical sensing system. The light source emits photons that reflect off user input objects, and the photodetector converts these optical signals into electrical signals for processing. This mechanical-to-optical substitution eliminates heavy mechanical components while preserving input functionality.
2Adaptability or versatility
If conventional touch input devices are used, then two-dimensional touch detection is enabled, but three-dimensional gesture and distance detection capabilities are lost
Solution Approach 1:
The patent extends input detection from two-dimensional touch surfaces to three-dimensional space by measuring the distance of user input objects from the device surface. The optical sensing system detects not only the presence and position of objects on the surface but also their distance along the Z-axis, enabling detection of gestures such as approaching, retreating, and hovering that provide rich 3D interaction capabilities.
Solution Approach 2:
The optical sensing system serves multiple functions: it detects 2D touch position, 3D distance, object approach velocity, and various gesture types. This multi-functional capability allows a single system to replace multiple specialized input devices, enhancing adaptability while maintaining ease of operation across different interaction modes.
3Reliability
If physical contact input devices are used, then reliable input detection is achieved, but the devices are restricted to contact-based input only
Solution Approach 1:
The patent introduces light as an intermediary medium between the user and the electronic device. Instead of requiring direct physical contact, the system uses light reflection from the user input object as a mediator to convey input information. This intermediary approach maintains reliable detection through consistent optical feedback while enabling diverse non-contact input methods such as waving, pointing, and hovering gestures.
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 method reduces hardware requirements, allows for versatile input on various surfaces, and enhances user interaction by detecting presses, motions, and gestures in three dimensions, improving device functionality and user experience.
Implementation Method 1
Reflections of the light beam from an object or the input surface may be received into the self-mixing interferometry sensor and induce self-mixing interference in a source of the light beam
Implementation Method 2
Reflections of the light beam from an object or the input surface may be received into the self-mixing interferometry sensor
Implementation Method 3
The source of the light beam may be a laser diode, such as a vertical cavity, surface emitting laser (VCSEL) diode
Implementation Method 4
The source of the light beam may be a laser diode
Data Source
AI summary
Disclosed herein are electronic devices, and methods for their operation, that identify user inputs based on interaction of an object with input surfaces separate from the electronic devices. The electronic devices may include one or more self-mixing interferometry sensors that scan a field of view containing the input surface with a light beam, such as a laser beam emitted laser diode. Self-mixing of the emitted light with reflections can generate a self-mixing interferometry signal. Analysis of the self-mixing interferometry signal can allow for identification of an object, such as a user's finger, in the field of view. Deformation of the finger can be detected with the self-mixing interferometry sensor, and a user input identified therefrom.