Liquid Crystal Display Electrode Positioning for Sensor Noise Reduction
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Solution Overview
Problem
In liquid crystal display apparatuses, the signal-to-noise ratio of received light data from photo-sensor elements is often compromised due to noise interference from electric field electrodes, particularly in FFS mode where the common electrode is proximal to the photo-sensor, leading to inaccurate detection of object positions.
Innovation Solution
The liquid crystal display apparatus is designed with electrodes positioned outside the light receiving area of the photo-sensor element, and a filter layer that transmits more infrared rays than visible rays is used to improve the signal-to-noise ratio by reducing noise interference, specifically using a visible ray cut filter layer that includes red, green, and blue filter layers laminated to enhance infrared transmission while blocking visible rays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the common electrode is positioned close to the photo-sensor element in FFS mode, then the liquid crystal display can achieve proper display function, but noise interference from the electrode coupling increases and degrades the signal-to-noise ratio of received light data
Solution Approach 1:
The harmful electromagnetic field from the common electrode is extracted and removed from the light receiving area by positioning the electrode outside this region. This separation eliminates the source of noise interference while preserving the electrode's essential function of applying electric field to the liquid crystal layer in non-light-receiving areas.
Solution Approach 2:
The patent applies different spatial configurations to different functional regions: the common electrode is positioned in regions where it can fulfill its display function while avoiding the light receiving area of the photo-sensor element. This local differentiation ensures that the electrode provides necessary electric field control where needed while minimizing interference where detection is critical.
2Adaptability or versatility
If a separate touch panel is added to the liquid crystal display, then touch detection function is achieved, but the device size and thickness increase
Solution Approach 1:
The patent merges the touch detection photo-sensor element with the liquid crystal display panel structure itself. The photo-sensor element is integrated into the pixel region and shares the same substrate and structural layers as the display, eliminating the need for a separate touch panel component and thereby reducing overall device thickness.
Solution Approach 2:
The liquid crystal display panel is designed to serve multiple functions: it provides both display output through the liquid crystal layer and touch detection through the integrated photo-sensor element. This multi-functionality allows a single component to replace what would traditionally require separate display and touch panel assemblies.
3Adaptability or versatility
If the photo-sensor element is positioned in the pixel region to enable touch detection, then touch detection function is achieved, but noise from electrode coupling degrades the detection accuracy
Solution Approach 1:
The harmful electromagnetic interference from the common electrode is extracted and removed from the photo-sensor element's light receiving area. By positioning the common electrode outside the light receiving area, the patent eliminates the primary source of noise that would otherwise couple with the photo-sensor element and degrade detection accuracy.
Solution Approach 2:
The patent creates a localized noise-free zone around the photo-sensor element's light receiving area by strategically positioning the common electrode in non-light-receiving regions. This local quality differentiation ensures high detection accuracy in the photo-sensor region while maintaining proper electrode function in other areas of the pixel region.
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 improves the signal-to-noise ratio of received light data, enabling more precise detection of object positions by minimizing noise from electrode coupling and maintaining image quality.
Implementation Method 1
a photo-sensor element having a light receiving face at which the photo-sensor element receives incident light through the liquid crystal layer in the pixel region to produce received light data
Implementation Method 2
a filter layer that transmits more infrared rays than visible rays is used to improve the signal-to-noise ratio by reducing noise interference, specifically using a visible ray cut filter layer that includes red, green, and blue filter layers laminated
Data Source
AI summary
Disclosed herein is a liquid crystal display apparatus, including: a liquid crystal panel having a pixel region in which first and second electrodes apply an electric field to a liquid crystal layer to display an image; the liquid crystal panel including a photo-sensor element having a light receiving face at which the photo-sensor element receives incident light through the liquid crystal layer in the pixel region to produce received light data; at least one of the first and second electrodes being formed in a region of the pixel region other than a light receiving face corresponding region of the pixel region which corresponds to the light receiving face of the photo-sensor element.