Optical Proximity Sensor for 2D Touch Detection
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Solution Overview
Problem
Existing one-dimensional arrays of proximity sensors are not accurate enough to determine a two-dimensional location of a pointer within a two-dimensional plane, limiting their effectiveness in applications such as door lock systems, laptop touchscreen conversion, and in-vehicle infotainment systems.
Innovation Solution
A proximity sensor system using a one-dimensional array of alternating light emitters and detectors to provide two-dimensional touch detection, with a three-dimensional touch or hover detection capability, and a GUI for in-vehicle infotainment systems offering context-driven and hierarchical navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a one-dimensional array of proximity sensors is used, then the device complexity is reduced, but the measurement precision for two-dimensional location determination is insufficient
Solution Approach 1:
The patent applies dimensionality change by using a one-dimensional array of proximity sensors to detect two-dimensional touch locations. The system achieves 2D location determination by mathematically processing the depth information from multiple 1D sensor measurements, effectively converting a 1D physical array into a 2D detection capability through computational geometry and trigonometric calculations.
2Measurement precision
If alternating light emitters and detectors are used in a one-dimensional array, then two-dimensional touch detection capability is enabled, but the device complexity increases
Solution Approach 1:
The patent segments the touch detection function into multiple independent light emitters and detectors arranged in alternating positions along a one-dimensional array. Each emitter-detector pair independently measures depth at its specific location, and the system integrates these segmented measurements to reconstruct the complete two-dimensional touch location, thereby achieving 2D detection through 1D segmentation.
3Adaptability or versatility
If three-dimensional touch or hover detection is implemented, then the functionality is enhanced, but the difficulty of detecting and measuring increases
Solution Approach 1:
The patent introduces light as an intermediary medium to enable three-dimensional touch and hover detection. Light emitters project light into the detection volume, and light detectors receive reflected or scattered light from objects at different 3D positions. The system uses light travel time, intensity, and angular information as intermediaries to calculate three-dimensional coordinates, making 3D detection feasible through optical mediation.
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
Enables accurate two-dimensional touch detection and three-dimensional gesture recognition, enhancing user interaction in various applications by converting non-touchscreen laptops into touchscreen devices and providing intuitive navigation in vehicle infotainment systems.
Implementation Method 1
a plurality of light detectors for detecting reflections of the light projected by the emitters by a reflective object in the detection plane
Data Source
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AI summary
A proximity sensor including a housing, light emitters in the housing projecting light out of the housing along a detection plane, light detectors in the housing detecting amounts of light entering the housing along the detection plane, whereby for each emitter-detector pair (E, D), when an object is located at a target position p(E, D) in the detection plane, corresponding to the pair (E, D), then light emitted by emitter E is scattered by the object and is expected to be maximally detected by detector D, and a processor to synchronously activate emitter-detector pairs, to read the detected amounts of light from the detectors, and to calculate a location of the object in the detection plane from the detected amounts of light, in accordance with a detection-location relationship that relates detections from emitter-detector pairs to object locations between neighboring target positions in the detection plane.