Dual-Unit Light Detection Circuit for Ambient Light Noise Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light detection elements in displays face inaccuracies due to dark display content and ambient light interference, leading to incorrect detection results.
Innovation Solution
A light detection element comprising a first and second light detection unit, a driving transistor, and a control circuit that synchronizes the operation of transistors to reduce noise impact by distinguishing between reflected and direct light, using a feedback circuit to control signal transmission and prevent misjudgment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pixel light source is used as a detection light source to detect reflected light, then the light detection element can determine touch position, but the detection result is affected by dark display content and changes in color and brightness of display content, causing incorrect detection
Solution Approach 1:
The light detection element is divided into multiple detection units (first light detection unit and second light detection unit) that can independently detect light from different sources. This segmentation allows the system to distinguish between display content light and ambient light, eliminating interference from dark display content and color/brightness changes.
2Ease of operation
If the light detection element detects reflected light to determine touch position, then touch detection function is achieved, but the light detection element is easily affected by ambient light during detection
Solution Approach 1:
A third light source is introduced as an intermediary to provide a reference signal for ambient light detection. The second light detection unit detects light from this third source, allowing the system to measure and compensate for ambient light interference, thereby maintaining accurate touch detection functionality.
3Measurement precision
If the first transistor is turned on to detect reflected light, then reflected light detection is enabled, but noise interference occurs leading to misjudgment
Solution Approach 1:
The system implements feedback mechanisms where detection results from multiple units are processed by a control circuit. The control circuit analyzes signals from both the first and second light detection units, using feedback loops to distinguish valid reflected light signals from noise, thereby preventing misjudgment while maintaining detection accuracy.
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
The solution effectively reduces noise interference, enhancing the accuracy of light detection by differentiating between reflected and direct light, thereby improving the reliability of touch position determination.
Implementation Method 1
The gate terminal is electrically connected to the first light sensing unit and the second light sensing unit
Data Source
AI summary
A light detection element, including a first light detection unit, a second light detection unit, and a driving transistor, is provided. The first light detection unit includes a first transistor and a first light sensing unit. The first transistor and the first light sensing unit are electrically connected. The second light detection unit and the first light detection unit are electrically connected. The second light detection unit includes a second light sensing unit and a second transistor. The second light sensing unit and the second transistor are electrically connected. The driving transistor has a gate terminal. The gate terminal is electrically connected to the first light sensing unit and the second light sensing unit. In a time interval, the first transistor is not turned on and the second transistor is turned on.