Proximity Sensor Layout Using Dual Light Sensing Regions
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Solution Overview
Problem
Conventional proximity sensors struggle with accurately determining distance due to interference from undesired reflected light, lacking a proper mechanism to mitigate this issue.
Innovation Solution
A distance determining system with multiple light sensing regions and a processing circuit that computes distance information based on the relation between light intensities sensed by these regions, using calibrated light intensities to distinguish near and far ranges, and employs compensation parameters to reduce interference from undesired reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional proximity sensor uses a single light sensor to determine distance, then the device complexity is low, but the measurement precision is degraded due to interference from undesired reflected light
Solution Approach 1:
The sensor divides the light sensing function into multiple spatially separated light sensing regions (first light sensing region and second light sensing region) at different distances from the light source. Each region independently senses light intensity, and the processing circuit uses the relationship between these intensities to determine distance while compensating for undesired reflections, thereby improving measurement precision without excessive complexity increase
Solution Approach 2:
The patent introduces a processing circuit as an intermediary that receives light intensity signals from multiple light sensing regions and computes distance information based on the relationship between these intensities. This intermediary processes the raw sensor data to eliminate interference from undesired reflected light, achieving accurate distance determination while maintaining a manageable device structure
2Measurement precision
If a proximity sensor uses multiple light sensing regions at different distances, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The light sensing system is segmented into multiple distinct light sensing regions (first and second regions) positioned at different distances from the light source. Each region contains light sensing devices that independently measure light intensity, enabling the system to distinguish between desired and undesired reflected light based on intensity relationships, thus improving precision while keeping each individual sensing region relatively simple
Solution Approach 2:
Multiple light sensing regions serve multiple functions: they simultaneously detect light intensity from the target object and provide reference measurements for compensating undesired reflections. The processing circuit universally processes signals from all regions to compute distance information, making the system multi-functional while avoiding the need for separate complex compensation mechanisms
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
Accurately determines distance states and reduces interference from undesired reflected light, enhancing the precision of proximity sensing.
Implementation Method 1
compute distance information of an object which reflects the light to the first light sensing region and the second light sensing region
Implementation Method 2
a first light intensity sensed by the first light sensing region and a second light intensity sensed by the second light sensing region
Data Source
AI summary
A distance determining system comprising: a light source, configured to emit light; a first light sensing region, away from the light source for a first distance, comprising at least one first light sensing device; a second light sensing region, away from the light source for a second distance larger than the first distance, comprising at least one second light sensing device; and a processing circuit, configured to compute distance information of an object which reflects the light to the first light sensing region and the second light sensing region, according to a first relation between a first light intensity sensed by the first light sensing region and a second light intensity sensed by the second light sensing region.