Twisted Chiral Liquid Crystal Display Element for Low Voltage Operation
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Solution Overview
Problem
Conventional liquid crystal display elements using the Kerr effect require higher driving voltages due to limited molecular orientation and optical response primarily near the substrate surfaces, leading to low contrast and color distortion issues.
Innovation Solution
A display element with a twisted chiral structure formed by a dielectric material layer between substrates, where the optical anisotropy is changed by an electric field, allowing for low-voltage operation and wide viewing angles, and eliminating the need for alignment films to reduce light leakage and color distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional liquid crystal display elements using the Kerr effect are used, then molecular orientation and optical response occur near substrate surfaces, but higher driving voltages are required
Solution Approach 1:
The patent introduces a twisted chiral structure that fundamentally changes the molecular orientation behavior of the liquid crystal material. This structural parameter change enables the liquid crystal molecules to align in a twisted configuration rather than parallel to the substrate, allowing optical response throughout the entire liquid crystal layer thickness and reducing the required driving voltage while maintaining fast response speed.
Solution Approach 2:
The patent employs a composite structure combining liquid crystal material with chiral dopants to form a twisted chiral structure. This composite material approach creates a new molecular arrangement that enhances the electro-optical response throughout the bulk material, enabling low-voltage operation while preserving the fast response characteristics associated with surface-near molecular orientation.
2Stability of the object's composition
If alignment films are used in liquid crystal display elements, then molecular alignment is achieved, but light leakage and color distortion occur
Solution Approach 1:
The patent removes the alignment films from the display element structure entirely. By eliminating these films, the source of light leakage and color distortion is removed. The twisted chiral structure provides sufficient molecular alignment without requiring alignment films, thus achieving both good alignment and elimination of harmful optical effects.
Solution Approach 2:
The liquid crystal material with twisted chiral structure performs the alignment function that was previously provided by alignment films. The chiral structure itself guides the molecular orientation throughout the liquid crystal layer, making the alignment films redundant and enabling their removal to eliminate light leakage and color distortion issues.
3Illumination intensity
If liquid crystal molecules are oriented in a certain direction for display, then image display is achieved, but viewing angle is limited
Solution Approach 1:
The patent transitions from two-dimensional molecular orientation (parallel to substrate plane) to three-dimensional twisted orientation (throughout the liquid crystal layer thickness). This dimensional change in molecular arrangement allows light to be modulated effectively from multiple viewing angles, expanding the viewing cone while maintaining display brightness through the bulk material response.
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 achieves low driving voltage, high contrast, and wide viewing angles by utilizing a twisted chiral structure that changes optical anisotropy with an electric field, enhancing response speed and temperature stability in liquid crystal display devices.
Implementation Method 1
there is also a display method in which the secondary electro-optical effect is utilized. The electro-optical effect is a phenomenon in which a refractive index of a material is changed by an external electric field. There are two types of electro-optical effects: one is an effect proportional to the electric field and the other is an effect proportional to the square of the electric field. The former is called the Pockels effect; the latter is called the Kerr effect.
Implementation Method 2
The material layer includes a medium whose optical anisotropy magnitude is changeable by and according to the field, and in which a unique twisted chiral structure is formed when optical anisotropy occurs.
Data Source
AI summary
An electrode is provided on one surface of each of a pair of substrates. On the other surface of each of the substrates, a polarizer is provided. The substrates are assembled together so that their surfaces on which the electrodes are formed face each other. Then, a medium is introduced between the substrates, to form a dielectric material layer. The medium is prepared by mixing a chiral agent in a negative type liquid crystalline compound.