Reflective Liquid Crystal Display with In-Cell Touch and Afterimage Control
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Solution Overview
Problem
Current reflective liquid crystal display devices with built-in touch panels suffer from afterimage issues due to alignment disorder at pixel end portions, particularly in transverse electrical field modes like FFS, which hinder the realization of in-cell type touch panels capable of reflection mode display.
Innovation Solution
A liquid crystal display device design featuring a first substrate with reflective layers, electrodes, and alignment films, where belt-shaped portions on the electrodes extend parallel without bends, and a twist-aligned liquid crystal layer with specific alignment angles, combined with polarizers and phase difference layers, suppresses alignment disorder and afterimages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a transverse electrical field mode liquid crystal display device is used to enable in-cell type touch panel, then the device can achieve thin and lightweight construction with improved light transmittance, but alignment disorder occurs at pixel end portions causing afterimage
Solution Approach 1:
The patent applies different alignment film characteristics to different regions of the liquid crystal layer. Specifically, a first alignment film with first alignment characteristics is provided at a first region, and a second alignment film with second alignment characteristics is provided at a second region. This local differentiation allows the pixel end portions to maintain proper alignment while avoiding the afterimage problem, thus resolving the contradiction between thin panel construction and display quality.
2Adaptability or versatility
If one of the pair of electrodes is placed on the counter substrate side for reflective display, then the device can perform reflection mode display, but the in-cell type touch panel configuration cannot be realized
Solution Approach 1:
The patent inverts the conventional electrode placement configuration. Instead of placing one electrode on the counter substrate side as in conventional reflective displays, both electrodes are provided on the active matrix substrate side. This inversion enables the integration of touch panel functionality within the liquid crystal display structure, achieving in-cell type configuration while maintaining reflection mode display capability.
3Ease of manufacture
If belt-shaped portions of electrodes are designed with bending parts to accommodate pixel geometry, then the electrode can be formed continuously, but alignment disorder occurs at pixel end portions
Solution Approach 1:
The patent segments the electrode structure into multiple belt-shaped portions separated by slits. This segmentation allows each belt-shaped portion to be formed with straight lines extending substantially parallel to each other, avoiding bending parts that cause alignment disorder. The slits between the portions prevent the formation of continuous electrodes that would create alignment problems at pixel ends, thus resolving the contradiction between ease of manufacture and alignment precision.
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 design effectively reduces afterimage occurrence, enabling an in-cell type touch panel capable of reflection mode display with improved image quality and reduced power consumption.
Implementation Method 1
the liquid crystal layer takes a twist alignment when no voltage is applied
Implementation Method 2
a reflective layer that reflects light
Implementation Method 3
a first electrode and a second electrode configured to generate a transverse electrical field in the liquid crystal layer
Data Source
AI summary
To provide a liquid crystal display device including a plurality of pixels arrayed in a matrix shape that includes a first substrate, a second substrate, and a liquid crystal layer. The first substrate includes a reflective layer, a first electrode and a second electrode capable of generating a transverse electrical field in the liquid crystal layer, and a first horizontal alignment film, at least one of the first electrode and the second electrode includes a plurality of belt-shaped portions and a slit located between two adjacent belt-shaped portions of the plurality of belt-shaped portions, in each pixel, the plurality of belt-shaped portions have a linear shape extending substantially parallel to each other and in the same direction, and do not include a bending part, the second substrate includes a second horizontal alignment film and the liquid crystal layer takes a twist alignment when no voltage is applied.