Switchable Polarizer Display with Liquid Crystal Viewing Angle Control
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Solution Overview
Problem
Display devices lack the ability to seamlessly switch between private and public viewing modes, with existing technologies failing to provide both narrow and wide viewing angles effectively, compromising privacy and visibility.
Innovation Solution
A display device incorporating a liquid crystal layer between polarizers with perpendicular polarization directions and a phase difference layer, featuring openings in the polarizers to enhance optical efficiency and switch between private and public modes by altering the liquid crystal molecule orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a display device uses a single viewing angle configuration, then it can provide either wide viewing angle for public viewing or narrow viewing angle for privacy, but it cannot provide both modes
Solution Approach 1:
The display device dynamically changes its optical properties by switching between public and private viewing modes. The liquid crystal layer reorients its molecules in response to applied voltage, transforming the display from wide viewing angle mode to narrow viewing angle mode, enabling adaptive privacy control without physical restructuring
Solution Approach 2:
The display device incorporates multiple functions within a single optical stack: it can operate as both a public display with wide viewing angle and a private display with narrow viewing angle. The same polarizer-liquid crystal layer-polarizer structure serves dual purposes by changing its optical state, eliminating the need for separate display systems
2Use of energy by moving object
If openings are added to polarizers to improve optical efficiency, then light transmission is enhanced, but manufacturing complexity increases
Solution Approach 1:
The polarizers are segmented with openings that correspond to the pixel arrangement of the display. This segmentation allows light to pass through specific regions while blocking others, improving optical efficiency by directing light more effectively toward the viewer and reducing waste, while the segmented structure can be integrated into existing manufacturing processes
3Object-affected harmful factors
If perpendicular polarizers are used to achieve private viewing mode, then viewing angle is restricted for privacy, but external light reflection increases
Solution Approach 1:
The perpendicular polarizer configuration, which initially causes external light reflection as a harmful effect, is converted into a beneficial feature for privacy protection. The reflected external light is polarized perpendicular to the display output, making it invisible to viewers in private mode, thus transforming the reflection problem into an enhanced privacy mechanism
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 enables the display device to switch between private mode with a narrow viewing angle for privacy and public mode with a wide viewing angle, improving optical efficiency and reducing external light reflection in both modes.
Implementation Method 1
a liquid crystal layer disposed between the first polarizer and the polarizer
Implementation Method 2
a first polarizer disposed on the display module; a second polarizer disposed on the first polarizer; wherein a polarization direction of the first polarizer and a polarization direction of the second polarizer may be perpendicular (i.e., orthogonal) to each other
Implementation Method 3
The display device may further include a phase difference layer below the plurality of polarizers to reduce the reflection of external light even in the public viewing mode
Implementation Method 4
A plurality of openings overlapping the plurality of light emitting areas may be defined in one of the plurality of polarizers, and thus, the optical efficiency of the front light beams of the display device may be improved
Data Source
AI summary
A display device includes a display module that includes a plurality of light emitting areas and a non-light emitting area that surrounds the light emitting areas, a first polarizer disposed on the display module, a second polarizer disposed on the first polarizer, and a liquid crystal layer disposed between the first polarizer and the second polarizer. A plurality of openings are defined in the first polarizer or the second polarizer, and the openings overlap the light emitting areas. The display device is switchable between public and private viewing modes via an external input, in which a viewing angle of the display device in the private viewing mode is narrower than in the public viewing mode.