Ambient Light Sensor Exposure Switching for Screen-Light Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ambient light sensors in electronic devices suffer from low detection accuracy due to interference from screen light emissions and varying brightness levels, leading to inaccurate photo-generated currents and optical signals.
Innovation Solution
A light brightness detection method involving multiple exposure durations for optical sensors, with a determination step to stop detection when the output electrical signal falls within a predetermined range, using variable frequency driving to match exposure duration with ambient light conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single exposure duration is used for optical sensor detection, then the detection process is simple and fast, but the detection accuracy is low in varying brightness environments
Solution Approach 1:
The patent applies dynamics by making the exposure duration adjustable rather than fixed. The system dynamically selects different exposure durations based on ambient light conditions: using a first exposure duration for bright environments and a second exposure duration for dark environments. This dynamic adaptation resolves the contradiction by enabling accurate detection across varying brightness levels without requiring a permanently complex multi-sensor system.
Solution Approach 2:
The patent changes the exposure duration parameter according to ambient light conditions. By switching between different exposure duration values based on detected light levels, the system achieves accurate detection across different brightness environments. This parameter change approach allows a single sensor to adapt its characteristics to match environmental conditions, resolving the accuracy-complexity contradiction.
2Device complexity
If the optical sensor is placed below the display screen for compact design, then the device structure is simplified, but the detection accuracy deteriorates due to screen light interference
Solution Approach 1:
The patent applies preliminary action by performing detection during periods when the display screen is not emitting light (during black screen intervals). The system proactively schedules optical sensor detection to occur during these intervals, eliminating screen light interference before it can affect measurement accuracy. This timing-based separation resolves the contradiction between compact sensor placement and detection accuracy.
Solution Approach 2:
The patent skips the problematic period when screen light is emitted by performing detection only during black screen intervals. By rushing through the detection process during these brief windows when interference is absent, the system achieves accurate measurements despite the sensor's proximity to the display. This temporal skipping resolves the spatial constraint contradiction.
3Measurement precision
If multiple exposure durations are tested to improve accuracy, then detection accuracy improves across brightness ranges, but the detection time increases
Solution Approach 1:
The patent performs preliminary detection using a first exposure duration to quickly assess ambient light conditions. Based on this initial measurement, the system determines whether a second exposure duration is needed. This two-stage approach with preliminary screening reduces the average detection time while maintaining accuracy, as the second exposure is only performed when necessary.
Solution Approach 2:
The patent uses feedback from the first detection result to control whether the second detection is performed. If the first detection with one exposure duration provides sufficient accuracy, the process stops; otherwise, it proceeds to the second detection with a different exposure duration. This feedback-based conditional execution minimizes detection time while ensuring accuracy when needed.
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
Improves detection accuracy by adjusting exposure durations for optical sensors, ensuring accurate ambient light brightness determination across varying brightness levels.
Implementation Method 1
The ambient light sensor (also referred to as optical sensor) mainly uses an optical component to generate photocurrent under illumination to cause changes in the detection potential
Data Source
AI summary
A light brightness detection method, an electronic device, a processor and a computer program product. The method includes: a first detection step of detecting an output electrical signal of a first optical sensor within a first exposure duration; a second detection step of detecting an output electrical signal of a second optical sensor within a second exposure duration; and a determination step of stopping detection when an output electrical signal obtained in any one of the detection steps is within a predetermined electrical signal range. The method solves the problem of low detection accuracy of an ambient light sensor in the related art.