Off-Axis Proximity Sensor Design for Expanded Detection Window
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Solution Overview
Problem
Current light-based sensors for proximity and gesture detection on mobile communication devices are limited by a small detection window that requires user inputs to be provided directly over the sensor, restricting their usefulness as users interact primarily with keypads or touch screens.
Innovation Solution
The sensor design includes a housing with offset light paths and lens configurations that allow light to be transmitted and detected at angles relative to the sensor's major surface, enabling detection of objects beyond the traditional detection window, thus expanding the viewing range and allowing inputs without requiring direct alignment with the sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the sensor uses a traditional on-axis detection configuration, then the sensor structure is simple and compact, but the detection window is small and requires direct alignment with the sensor
Solution Approach 1:
The patent transitions from on-axis detection to off-axis detection by introducing an angular dimension to the light path. The light source and detector are positioned at an angle relative to the sensor surface normal, creating an oblique detection path that expands the detection window laterally without increasing the sensor's vertical profile or overall structural complexity.
Solution Approach 2:
The patent employs asymmetric positioning of the light source and detector relative to the sensor surface. Instead of symmetric on-axis alignment, the components are arranged with specific angular offsets and lateral displacements, creating an asymmetric optical path that enables detection of objects in extended angular ranges while maintaining a compact form factor.
2Ease of operation
If the sensor requires direct alignment with the detection window, then the optical path is simple, but the ease of operation is reduced as users must place inputs directly over the sensor
Solution Approach 1:
The patent introduces angular and lateral dimensions to the detection path, allowing the sensor to detect objects that are offset from the sensor surface. This enables users to provide inputs in a larger area around the sensor rather than requiring precise placement directly over the sensor, significantly improving ease of operation.
Solution Approach 2:
The patent uses optical elements such as lenses and reflectors as intermediaries to redirect light paths. These intermediaries enable the detection of oblique light paths from objects positioned away from the sensor, effectively extending the operational zone without requiring complex direct-line-of-sight configurations.
3Adaptability or versatility
If the sensor uses off-axis light paths, then the viewing range is expanded, but the manufacturing precision requirements increase due to offset light paths and lens configurations
Solution Approach 1:
The patent integrates the light source, detector, and optical elements into a unified sensor assembly where the off-axis optical path is built-in from the outset. By merging these components into a pre-aligned module, the patent eliminates the need for precise field alignment during assembly, reducing manufacturing precision requirements despite the complex optical geometry.
Solution Approach 2:
The patent designs the optical elements and component positions to self-align or self-correct for minor manufacturing tolerances. The optical path geometry and component mounting structures are configured to automatically compensate for small misalignments, reducing the stringency of manufacturing precision requirements while maintaining expanded viewing capabilities.
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 configuration allows for a compact form factor while enabling detection of objects and gestures outside the traditional detection zone, enhancing the usability of light-based sensors in mobile devices by allowing inputs to be recognized over a wider field of view and at varying distances.
Implementation Method 1
A sensor is provided including a housing, a light source mounted in the housing and configured to emit light, and a light detector mounted in the housing and configured to detect light
Implementation Method 2
The sensor design includes a housing with offset light paths and lens configurations that allow light to be transmitted and detected at angles relative to the sensor's major surface
Data Source
AI summary
An optical sensor for detecting at least one of proximity and gesture is disclosed. The optical sensor is configured to detect or sense an object that is located out of the sensor's primary axis. This off-axis detection is facilitated by projecting light emitted by a light source away from the sensor's primary axis and away from the direction in which the light was originally emitted by the light source. The light detector is also configured to detect the light that is being projected off-axis.