Alternating Common Electrodes Reduce LCD Power Consumption
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Solution Overview
Problem
The existing lateral electric field liquid crystal display devices have high power consumption due to a constant common voltage, which increases the data voltage required for pixel electrodes, leading to inefficient energy use.
Innovation Solution
The implementation of a liquid crystal display device with alternating common electrodes receiving different voltages and a shield electrode structure to reduce the data voltage needed, achieved through a driving method that inverts the polarity of pixel voltages for each column or row, allowing for lower voltage operation and reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a constant common voltage is applied to the common electrode, then the lateral electric field liquid crystal display device achieves wide viewing angle characteristics, but the data voltage increases leading to high power consumption
Solution Approach 1:
The common electrode is divided into multiple independent common electrodes (first common electrode and second common electrode) that can be supplied with different voltages. This segmentation allows the application of alternating voltages to adjacent common electrodes, creating a voltage pattern that reduces the required data voltage while maintaining the lateral electric field effect for wide viewing angle display.
Solution Approach 2:
Different regions of the display (adjacent pixel columns or rows) are supplied with different common voltages (first voltage and second voltage). This local variation in voltage creates a more efficient electric field distribution, reducing the overall voltage swing required and thereby lowering power consumption while preserving wide viewing angle characteristics.
2Use of energy by moving object
If alternating common electrodes with different voltages are applied, then power consumption is reduced, but the device complexity increases due to additional voltage supply requirements
Solution Approach 1:
The first common electrode and second common electrode are merged into a single common electrode structure in terms of physical layout and function, but electrically separated to allow different voltages. This merging approach maintains structural simplicity while enabling the complex voltage pattern needed for reduced power consumption.
Solution Approach 2:
The common electrode structure serves multiple functions: it provides the lateral electric field for wide viewing angle display and simultaneously acts as a voltage division structure that reduces power consumption. The same physical structure achieves both display quality and energy efficiency goals.
3Use of energy by moving object
If shield electrodes are added to overlap data signal lines and gate signal lines, then power consumption is further reduced through electric field shielding, but the device structure becomes more complex
Solution Approach 1:
Shield electrodes are introduced as intermediary elements between the data signal lines/gate signal lines and the liquid crystal layer. These shield electrodes, supplied with appropriate voltages, act as mediators that control and confine the electric field, preventing field leakage and reducing the overall voltage required, thereby lowering power consumption while adding minimal structural complexity.
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 lowers the data voltage required, reducing power consumption and costs while maintaining high aperture ratios and image quality, thereby enhancing the energy efficiency and cost-effectiveness of the liquid crystal display device.
Implementation Method 1
an electric field in a direction parallel to the substrate (lateral electric field) is generated between the pixel electrode and the common electrode so that the lateral electric field is applied to the liquid crystal to drive the liquid crystal
Implementation Method 2
a plurality of shield electrodes overlapping, through intermediation of an insulating film, at least one of the plurality of data signal lines and the plurality of gate signal lines
Data Source
AI summary
Provided is a liquid crystal display device, including a first and second substrates, the second substrate including data signal lines, gate signal lines, pixel electrodes, a plurality of common electrodes that extend in one of a column direction and a row direction, and a plurality of shield electrodes overlapping at least one of the data signal lines or the gate signal lines, the plurality of common electrodes including a first common electrode to which a first voltage is supplied and a second common electrode to which a second voltage is supplied, the first common electrode and the second common electrode being alternately arranged in one of the row direction and the column direction, in which, in plan view, each of the plurality of shield electrodes is formed to overlap at least a gap formed between the first common electrode and the second common electrode that are adjacent to each other.