OLED Ambient Light Sensor Polarization Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The measurement accuracy of ambient light intensity in mobile terminals equipped with OLED screens is compromised due to the self-emitting light intensity from the screens, which interferes with the light sensors' ability to accurately detect ambient light.
Innovation Solution
The implementation of two light sensors and a polarizer system, where one sensor measures ambient light and the other measures light intensity from the self-emitting layer, with polarizers filtering out ambient light from reaching the first sensor and self-emitting light from reaching both sensors, allowing for the calculation of ambient light intensity by determining the difference between their measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light sensor is disposed under the OLED screen to detect ambient light intensity, then the mobile terminal can adaptively adjust screen brightness, but the self-emitting light from the OLED screen interferes with the light sensor's measurement accuracy
Solution Approach 1:
The light sensing function is divided into two independent light sensors instead of using one sensor for both ambient light detection and self-emitting light measurement. This segmentation allows each sensor to have dedicated optical paths with specific polarizer configurations, enabling simultaneous measurement of ambient light and screen-emitted light without mutual interference.
Solution Approach 2:
Polarizers are introduced as intermediary components in the optical paths of both light sensors. The polarizers act as mediators that selectively filter light based on polarization directions, allowing the system to distinguish between ambient light and self-emitting light from the OLED screen, thereby resolving the measurement interference problem.
2Measurement precision
If polarizers are introduced to filter light for accurate ambient light detection, then measurement accuracy improves, but device complexity increases due to additional optical components
Solution Approach 1:
The polarizer components serve multiple functions simultaneously: they filter ambient light for the first light sensor, block self-emitting light from reaching both sensors, and enable the second sensor to measure only screen-emitted light. This multi-functionality reduces the need for additional separate filtering components, thereby limiting the increase in device complexity while achieving accurate measurement.
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 effectively reduces the influence of self-emitting light on ambient light measurement accuracy, enhancing the overall accuracy of ambient light detection and enabling adaptive screen brightness adjustments.
Implementation Method 1
an incident light path of the ambient light to the first light sensor passes through the first polarizer and a second polarizer, and polarization directions of the first polarizer and the second polarizer are perpendicular
Implementation Method 2
a first polarizer and a quarter phase retarder are disposed on the first optical path
Implementation Method 3
The light sensor can obtain ambient light intensity of front area of the screen of the mobile terminal
Data Source
AI summary
A mobile terminal includes: a body, an organic light-emitting diode (OLED) screen component over a surface of the body, a first light sensor, and a second light sensor. The OLED screen component includes: a self-emitting light layer and a light transmitting functional layer above the self-emitting light layer; at least one optical microhole in the self-emitting light layer; the first and second light sensors are disposed under the self-emitting light layer and at positions corresponding to the optical microhole; a first polarizer and a quarter phase retarder are disposed on the first optical path; an incident light path of a ambient light to the first light sensor passes through the first polarizer and a second polarizer, and polarization directions of the first polarizer and the second polarizer are perpendicular; an incident light path of the ambient light to the second light sensor passes through the first polarizer.