Dual-Panel Transflective Display with Reflective Polarizer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transflective display apparatuses have low light use efficiency and high power consumption due to the division of pixels into transmissive and reflective regions, leading to reduced contrast and increased parallax when switching between modes.
Innovation Solution
A display apparatus with a first and second display panel, a light reflective polarizer, and a backlight unit, where the first panel uses cholesteric liquid crystal with a reflection region outside the visible light spectrum, allowing for improved light transmission and reflection modes with reduced parallax by adjusting the electric field state of the liquid crystal layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If pixels are divided into transmissive and reflective regions in a transflective display apparatus, then both reflective and transmissive modes can be supported, but light use efficiency deteriorates and power consumption increases
Solution Approach 1:
The display apparatus is segmented into two separate display panels: a first display panel for reflective mode and a second display panel for transmissive mode. Each panel is dedicated to its specific function, eliminating the need to divide pixels into different regions. This segmentation allows each panel to operate at full efficiency in its designated mode without compromising the other.
Solution Approach 2:
The display apparatus achieves multi-functionality by incorporating both a reflective display panel and a transmissive display panel within the same system. The backlight unit serves both panels, and the control system manages both modes, allowing the apparatus to function as either a reflective or transmissive display depending on the operating mode selected.
2Adaptability or versatility
If pixels are divided into transmissive and reflective regions, then both modes can be supported, but contrast ratio deteriorates
Solution Approach 1:
By separating the display into two distinct panels with dedicated functions, each panel can optimize its liquid crystal layer and optical components for its specific mode. The reflective panel uses optimized reflective elements and the transmissive panel uses optimized backlight integration, resulting in superior contrast ratios for each mode without the compromises inherent in region-divided designs.
3Adaptability or versatility
If a transflective display apparatus is used in transmissive or reflective mode, then both modes are supported, but parallax phenomenon increases
Solution Approach 1:
The parallax issue is resolved by segmenting the display into separate panels that are optimized for their respective modes. The reflective panel is designed specifically for reflective operation with appropriate optical path considerations, while the transmissive panel is designed for backlight integration. This separation eliminates the optical path conflicts and parallax effects that occur when a single panel must accommodate both modes.
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
Enhances light use efficiency, reduces power consumption, and minimizes parallax by enabling efficient light management and grayscale representation in both reflective and transmissive modes.
Implementation Method 1
The light reflective polarizer is interposed between the first and second display panels to transmit light polarized in a first direction, and to reflect light polarized in a second direction substantially perpendicular to the first direction
Implementation Method 2
The cholesteric liquid crystal layer is interposed between the first and second substrates, and includes a reflection region having a wavelength shorter than or longer than a wavelength of visible light. When substantially no electric field is applied to the cholesteric liquid crystal layer, it is maintained in a planar state, so as to transmit light. When an electric field is applied to the cholesteric liquid crystal layer, it is maintained in a focal conic state to scatter incident light
Implementation Method 3
The backlight unit is positioned proximate to the second display panel to supply light to the first and second display panels
Data Source
AI summary
A display apparatus includes a first display panel with a plurality of first pixels, a second display panel facing the first display panel and having a plurality of second pixels, a light reflective polarizer, and a backlight unit. The light reflective polarizer is interposed between the first and second display panels to transmit light polarized in a first direction, and reflect light polarized in a second direction substantially perpendicular to the first direction. The backlight unit is arranged proximate to the second display panel to supply light to the first and second display panels. The first display panel displays an image by using reflected ambient light, and the second display panel displays an image by using light from the backlight unit.