Blue Phase Liquid Crystal Display with Dual-Side Interdigit Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices using blue phase liquid crystals face issues with low light transmittance and high drive voltage requirements, leading to increased power consumption and inability to use low-voltage drive switching devices, due to weak electric field intensity and optical-anisotropy limitations above interdigit electrodes.
Innovation Solution
An electro-optical device design with transparent electrodes and polarizing plates arranged to impart optical-anisotropy to the medium layer above the electrodes, allowing for high transmittance and low-voltage operation by applying electric fields parallel to the substrates and minimizing electrode gaps to enhance optical-anisotropy overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If interdigit electrodes are used to apply electric field to blue phase liquid crystal, then high-speed response is achieved, but light transmittance decreases and drive voltage increases
Solution Approach 1:
The patent applies electric fields from both upper and lower substrates simultaneously, transitioning from a single-plane electrode configuration to a three-dimensional field application. This allows the electric field to penetrate through the liquid crystal layer more effectively, achieving both high-speed response and high transmittance while reducing required drive voltage.
Solution Approach 2:
The patent combines electrode groups on both upper and lower substrates to create a synergistic electric field effect. By merging the field application from both sides, the system achieves enhanced optical-anisotropy impartment throughout the liquid crystal layer, resolving the contradiction between response speed and transmittance.
2Speed
If electrode interval is made smaller to enhance electric field, then response speed improves, but electric field component parallel to substrate decreases
Solution Approach 1:
By applying electric fields from both upper and lower substrates, the patent creates a three-dimensional field distribution that compensates for the reduced parallel component. The vertical field components from both sides work together to maintain effective optical-anisotropy impartment even when electrode intervals are small.
Solution Approach 2:
The patent creates different field characteristics in different regions of the liquid crystal layer. The region between electrodes receives strong parallel field components for fast response, while the region above electrodes receives combined field components from both substrates that maintain sufficient optical-anisotropy for high transmittance.
3Illumination intensity
If transparent electrodes are used to improve transmittance, then light passes through electrode regions, but electric field intensity above electrodes remains weak
Solution Approach 1:
The patent combines the electric field contributions from upper and lower electrode groups to amplify the field intensity above the electrodes. This merging of field sources ensures that even in regions where single-sided field application would be weak, the combined effect maintains sufficient intensity for optical-anisotropy impartment.
Solution Approach 2:
The dual-sided electrode configuration transforms the field application from a two-dimensional surface effect to a three-dimensional volume effect, ensuring uniform and sufficient electric field intensity throughout the liquid crystal layer, including regions above the electrodes.
4Illumination intensity
If high voltage is applied to achieve optical-anisotropy above electrodes, then transmittance improves, but power consumption increases and low-voltage switching devices cannot be used
Solution Approach 1:
By merging the electric field effects from upper and lower electrode groups, the patent achieves sufficient optical-anisotropy impartment at lower voltages than would be required with single-sided electrode application. This enables the use of low-voltage drive switching devices while maintaining high transmittance.
Solution Approach 2:
The simultaneous application of electric fields from both substrates creates a continuous and uniform optical-anisotropy effect throughout the liquid crystal layer, eliminating the need for high peak voltages and enabling efficient low-voltage operation with standard drive switching devices.
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 high light transmittance and contrast with improved display quality, reducing power consumption and enabling efficient low-voltage operation in liquid crystal display devices.
Implementation Method 1
The optical-anisotropy is imparted to a region of the medium layer above the plurality of transparent electrodes in a direction normal to the plurality of substrates by at least two of the plurality of electrode groups
Implementation Method 2
an electro-optical device including a plurality of substrates which are opposed to and parallel to each other; a medium layer sandwiched between the plurality of substrates
Implementation Method 3
a pair of polarizing plates which are arranged so that absorption axes thereof are substantially orthogonal to each other with the medium layer sandwiched between the pair of polarizing plates
Data Source
AI summary
Provided is an electro-optical device which allows high-speed response and has high luminance and contrast. The electro-optical device includes: a plurality of substrates opposed to each other; a medium layer sandwiched between the substrates; electrode groups formed on opposed surfaces of the substrates, for applying an electric field to the medium layer, the electrode groups having a portion in which the electrode groups have an interdigit shape and are arranged substantially parallel; and a pair of polarizing plates which are arranged so that absorption axes thereof are substantially orthogonal to each other with the medium layer sandwiched therebetween, in which the medium layer includes a medium substantially having optical-isotropy with absence of an electric field and exhibiting optical-anisotropy with an applied electric field, the electrode groups include transparent electrodes, and the optical-anisotropy is imparted near the respective electrodes in a direction normal to the substrates by the electrode groups.