Optical Sensor Front End for Ambient and RF Light Separation
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Solution Overview
Problem
Existing optical sensor systems lack the capability to effectively distinguish between ambient light and radio frequency (RF) light signals, which limits their ability to accurately detect proximity and motion in various applications, particularly in environments with mixed light sources.
Innovation Solution
The optical sensor system incorporates a front end that separates detected light signals into ambient light and RF light components, using a combination of gain circuitry, demodulation, and low-pass filtering to produce distinct output signals for proximity and motion detection, allowing for independent detection of stationary and moving objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensor systems use a single light detector to detect light signals, then the system can detect light presence, but it cannot distinguish between ambient light and RF light signals from the light source
Solution Approach 1:
The patent segments the detected light signal into two distinct components: ambient light signal (low frequency) and RF light signal (high frequency). By separating the signal processing paths for these two components, the system can independently analyze and respond to each type of light, enabling accurate distinction between ambient and source-generated light without requiring multiple physical detectors.
Solution Approach 2:
The patent introduces frequency-based signal separation as an intermediary mechanism between the light detector and the processing channels. The front end circuitry acts as an intermediary that filters and routes different frequency components to appropriate processing paths, allowing the system to distinguish between ambient and RF light signals while maintaining a single detector architecture.
2Measurement precision
If the system detects both ambient light and RF light signals simultaneously, then it can gather comprehensive light information, but it cannot independently detect proximity and motion in mixed light environments
Solution Approach 1:
The patent creates separate processing channels for ambient light and RF light signals. The proximity channel processes RF light signals to detect object proximity, while the motion channel processes RF light signals to detect object motion. This segmentation allows independent optimization of each detection function without interference from ambient light variations.
Solution Approach 2:
The system dynamically adjusts signal processing based on the detected signal characteristics. The front end circuitry dynamically separates signals based on their frequency content, routing low frequency components to the ambient light channel and high frequency components to the proximity and motion channels. This dynamic separation enables the system to adapt to mixed light environments while maintaining accurate detection capabilities.
3Productivity
If the system processes the entire detected light signal through a single channel, then the processing is simple, but it cannot produce independent proximity and motion detection outputs
Solution Approach 1:
The patent segments the signal processing architecture into distinct channels: an ambient light channel for processing low frequency components, a proximity channel for processing RF light signal components related to object proximity, and a motion channel for processing RF light signal components related to object motion. This segmentation enables the system to produce multiple independent detection outputs while maintaining efficient processing through frequency-based separation.
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 solution enables the system to accurately detect proximity and motion independently of ambient light levels, enhancing its performance in diverse applications by distinguishing between low and high frequency components of the detected light signals.
Implementation Method 1
a light detector, wherein the sensor can estimate proximity of an object based on the magnitude of reflected light from the one or more LED returning to the sensor
Implementation Method 2
A distinction between the detected ALS and the detected RF light signal is that the detected ambient light signal includes the low frequency components of the detected light signal, whereas the detected RF light signal includes the high frequency components of detected light signal
Data Source
AI summary
Provided herein are optical sensor systems that can be used for ambient light detection, proximity detection and motion detection, as well as to larger systems that include such an optical sensor system, and to related methods. In an embodiment, the optical sensor system includes a front end, an ambient light channel, a proximity channel and a motion channel. In an embodiment, offset and gain of the proximity channel is adjusted based on motion detected by the motion channel.