Dual-Mode Liquid Crystal Display with Segmented Pixel Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices struggle to efficiently switch between reflective and transmissive modes, leading to reduced contrast and increased power consumption, especially in varying environmental lighting conditions.
Innovation Solution
A liquid crystal display device with a dual-mode capability, utilizing a pixel structure with both transmissive and reflective regions, where the transmissive region uses a backlight with LEDs for improved power efficiency and reduced color breakup, and the reflective region uses external light, with a novel field-sequential method for image display, and transistors with oxide semiconductors for low off-state current, allowing for longer voltage holding and reduced wiring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If a liquid crystal display device uses a reflective mode to reduce power consumption in bright environments, then power consumption is reduced, but contrast is degraded due to external light reflection
Solution Approach 1:
The pixel electrode is divided into two distinct regions: a transmissive region with a light-transmitting conductive material and a reflective region with a light-reflecting conductive material. This segmentation allows different portions of the pixel to perform different functions - the transmissive region allows backlight passage while the reflective region reflects external light, enabling the display to maintain contrast in bright environments while reducing power consumption
2Adaptability or versatility
If a liquid crystal display device switches between reflective and transmissive modes, then adaptability to different lighting environments is improved, but device complexity increases
Solution Approach 1:
The pixel electrode structure is designed to perform multiple functions within a single unified design. The same pixel electrode with its dual-region structure serves both reflective and transmissive display modes, eliminating the need for separate structures for each mode. This multi-functionality achieves adaptability to different lighting environments while controlling device complexity
Solution Approach 2:
The reflective region and transmissive region are integrated into a single pixel electrode structure within one pixel. A signal line is shared by both regions, and transistors control both regions, merging previously separate reflective and transmissive display functions into a unified structure, thereby reducing overall device complexity while maintaining adaptability
3Reliability
If a liquid crystal display device uses a transmissive mode with backlight to improve visibility in dim environments, then visibility is improved, but power consumption increases
Solution Approach 1:
The pixel electrode is segmented into transmissive and reflective regions, allowing the display to selectively use the transmissive region with backlight for improved visibility in dim environments while controlling power consumption through the light-reflecting region
Solution Approach 2:
The display device periodically switches between reflective and transmissive modes based on ambient lighting conditions. In dim environments, the transmissive mode is activated with backlight illumination, while in bright environments, the reflective mode is used, creating a periodic action that optimizes both visibility and power consumption
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 device achieves efficient image display in both bright and dim environments by reducing contrast loss and power consumption, with improved color stability and extended image retention times.
Implementation Method 1
a state in which light from the backlight is transmitted through a liquid crystal and output to the outside of the liquid crystal display device or a state in which light is not output is selected using optical modulation action of liquid crystal
Implementation Method 2
a state in which external light, in other words, incident light is reflected at a pixel electrode and output to the outside of the device
Data Source
AI summary
A reflective region where display is performed with reflection of incident light through a liquid crystal layer and a transmissive region where display is performed by transmission of light from a backlight are provided, and the reflective mode and the transmissive mode are switched. In the case of displaying a full-color image, a pixel portion includes at least a first region and a second region, a plurality of lights of different hues are sequentially supplied to the first region according to a first order, and a plurality of lights of different hues are also sequentially supplied to the second region according to a second order which is different from the first order. In the transmissive mode, the reflective region is made to display black, so that decrease in contrast due to reflection of external light at the reflective region is prevented.