Liquid Crystal Display Device with Reflective Region for Power Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices face challenges in reducing power consumption and preventing image quality deterioration, particularly in field sequential driving methods where color break-up occurs and power consumption is high, especially in mobile devices.
Innovation Solution
A liquid crystal display device with a pixel portion divided into transparent and reflective regions, using a transistor with an oxide semiconductor for low off-state current, allowing for sequential lighting of multiple light sources of different hues and switching between full-color and monochrome modes, and utilizing external light or a backlight based on the environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If field sequential driving is used to reduce power consumption and eliminate color filters, then power consumption is reduced and light loss is minimized, but color break-up occurs and image quality deteriorates
Solution Approach 1:
The pixel electrode is divided into multiple regions (first region, second region, third region) that are sequentially driven with different colored lights. This segmentation allows the display to show different colors in different regions at different times, eliminating the need for color filters while maintaining image quality through spatial and temporal separation of color information.
Solution Approach 2:
The patent implements periodic switching of light sources with different hues (red, green, blue) to illuminate different regions of the pixel electrode in sequence. This periodic action creates the illusion of full-color display through temporal multiplexing, reducing power consumption by turning off the backlight during non-display periods while maintaining reliable color reproduction.
2Loss of energy
If field sequential driving is used to eliminate color filters, then light loss is reduced, but separate perception of colors without synthesis occurs
Solution Approach 1:
The patent adds a spatial dimension to the field sequential driving by dividing the pixel electrode into multiple regions that are illuminated sequentially with different colors. This spatial segmentation combined with temporal sequencing allows color information to be synthesized across different regions and time periods, eliminating color break-up while maintaining high light efficiency without color filters.
Solution Approach 2:
The patent applies preliminary action by pre-dividing the pixel electrode into multiple regions and pre-assigning different colored lights to different regions before sequential illumination. This preparation ensures that when lights are switched, the color information is already spatially organized, enabling proper color synthesis without break-up while maximizing light utilization.
3Use of energy by moving object
If mobile electronic devices require lower power consumption, then energy efficiency improves, but image quality deterioration becomes more critical
Solution Approach 1:
The patent changes multiple parameters simultaneously: it modifies the driving frequency to be optimized for human perception rather than maximum speed, adjusts the sequential illumination timing across different pixel regions, and varies the hue of lights applied to different regions. These parameter changes enable significant power reduction in mobile devices while maintaining acceptable image quality through optimized temporal and spatial display characteristics.
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 reduces power consumption, prevents color break-up, and allows for efficient image display in both reflective and transmissive modes, maintaining image quality with lower driving frequencies and reduced light loss.
Implementation Method 1
a liquid crystal layer
Implementation Method 2
a reflective region, external light is reflected by the reflective region
Data Source
AI summary
A liquid crystal display device comprising a backlight and a pixel portion including first to 2n-th scan lines, wherein, in a first case of expressing a color image, first pixels controlled by the first to n-th scan lines are configured to express a first image using at least one of first to third hues supplied in a first rotating order, and second pixels controlled by the (n+1)-th to 2n-th scan lines are configured to express a second image using at least one of the first to third hues supplied in a second rotating order, wherein, in a second case of expressing a monochrome image, the first and second pixels controlled by the first to 2n-th scan lines are configured to express the monochrome image by external light reflected by the reflective pixel electrode, and wherein the first rotating order is different from the second rotating order.