Proximity Sensor Ratio Detection for Display Reflection Interference
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Solution Overview
Problem
Proximity sensors placed behind display elements face interference from reflection components, making it difficult to accurately detect objects at a distance due to high reflection interference, leading to inaccurate determination of object presence.
Innovation Solution
The use of two sensors placed at different distances from an optical emitter, calculating a ratio of reflection signals to determine object presence, with an electronic control unit (ECU) comparing this ratio to thresholds to determine if an object is present and taking appropriate actions, such as turning off the display screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a proximity sensor is placed behind display elements to increase usable screen area, then the screen's usable area is increased, but reflection interference from display components increases making object detection inaccurate
Solution Approach 1:
The system segments the reflection detection function by using two separate sensors positioned at different distances from the optical emitter. The first sensor detects reflections from display components while the second sensor detects reflections from objects. By separating these detection functions spatially, the system can distinguish between display reflections and object reflections, maintaining measurement precision while preserving full-screen placement of the sensor.
Solution Approach 2:
The system adds a spatial dimension to the detection system by positioning sensors at different distances from the optical emitter along the optical path. This dimensional separation allows the system to differentiate between near-field reflections (from display components) and far-field reflections (from objects), resolving the contradiction between full-screen placement and accurate detection.
2Illumination intensity
If reflection signals from display components are high, then the display structure reflects sufficient light, but it interferes with detecting reflections from objects at higher distances
Solution Approach 1:
The system uses feedback by continuously monitoring reflection signals at two different distances and dynamically calculating the ratio between them. This ratio-based feedback mechanism allows the system to adapt to varying display reflection conditions and accurately determine object presence regardless of the absolute reflection intensity, resolving the contradiction between sufficient reflection and reliable detection.
Solution Approach 2:
The system changes the detection parameter from absolute reflection intensity to a ratio of reflection intensities at two different distances. This parameter transformation allows the system to maintain sensitivity to object reflections while being insensitive to variations in display component reflections, as the ratio remains relatively stable when only display reflections are present but changes significantly when object reflections are added.
3Device complexity
If a single sensor is used to detect object presence, then the device complexity is low, but the ability to differentiate between display reflections and object reflections is insufficient
Solution Approach 1:
The detection function is segmented into two separate sensing channels with sensors positioned at different distances from the optical emitter. This segmentation enables the system to differentiate between display component reflections and object reflections by comparing the relative strengths of signals received at the two sensor positions, achieving accurate reflection source identification with a relatively simple dual-sensor configuration.
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 effectively differentiates between reflections from objects and display components, allowing for accurate detection of object presence and absence, preventing accidental commands and improving user experience by ensuring correct operation of electronic devices.
Implementation Method 1
measure return signals when the IR emitter emits a signal
Implementation Method 2
The reflected signals are detected by the first and second sensors
Data Source
AI summary
The present disclosure describes a method and apparatus that can be used to determine whether an object is in proximity of an electronic device. When an object is not in proximity to the electronic device, the arrangement of two sensors at different distances from the optical emitter results in a higher strength of a reflection signal received in the sensor closer to the optical emitter and a lower strength of a reflection signal received in the sensor further from the optical emitter. The system uses this difference in reflection signals to calculate a ratio between the signals that are being reflected to both sensors, and based on the ratio whether an object is in proximity to the electronic device.