Switchable Light Filter for Private Viewing Mode
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Solution Overview
Problem
Existing display technologies face challenges in providing a switchable light filter that can toggle between public and private viewing modes without significant brightness reduction, complex optical elements, or high costs, while maintaining resolution and being universally applicable to various display screens.
Innovation Solution
A switchable light filter using a first optical element with multiple layers of light-absorbing transition dipole moments, a polarization filter, and a liquid crystal layer, which can be configured to transmit or absorb light based on its direction and polarization, allowing for angular limitations in transmission to be toggled between at least two operating states, enabling a protected view mode and a public view mode without reducing display resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If microlouver films are used for protected view, then viewing angle restriction is achieved, but light loss increases and the films are not switchable
Solution Approach 1:
The patent applies a switchable light filter that can dynamically change its optical properties between different viewing modes (public and private). The filter transitions from a static microlouver structure to a dynamic system that can be switched between transparent and privacy states, allowing users to adapt the viewing angle restriction to their needs while minimizing light loss when privacy is not required.
Solution Approach 2:
The invention changes the optical parameters of the light filter by using liquid crystal technology that can alter its refractive index and optical absorption characteristics based on applied voltage. This allows the filter to transition between different transmission states, achieving viewing angle restriction only when needed, thereby reducing overall light loss compared to permanent microlouver films.
2Manufacturing precision
If complex optical elements like microlens elements and prism structures are used, then light distribution control is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes the complex optical elements (microlens elements, prism structures) from the display system. Instead of using multiple specialized optical components to control light distribution, the invention achieves the desired light control function through a simplified switchable light filter that directly modulates light transmission based on viewing angle and polarization, eliminating unnecessary complexity.
Solution Approach 2:
The switchable light filter serves multiple functions that were previously requiring separate optical elements: it controls light distribution, provides viewing angle restriction, and enables privacy protection all through a single integrated component. This multi-functional approach reduces device complexity while maintaining effective light distribution control.
3Adaptability or versatility
If switchable light filter with liquid crystal and polarization filter is used, then toggling between public and private modes is achieved, but light loss may occur
Solution Approach 1:
The patent utilizes polarization-based optical effects where the light filter changes its transmission characteristics based on the polarization state of incident light. By aligning the polarization filter with the liquid crystal orientation in the transparent state, maximum light transmission is achieved. In the privacy state, the liquid crystal reorientation causes polarization mismatch, blocking light without significant absorption losses, thus maintaining high efficiency during mode switching.
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 allows for efficient toggling between protected and public viewing modes with minimal light loss, maintaining display resolution and being cost-effective, while being universally applicable to different types of display screens.
Implementation Method 1
A liquid crystal layer which is acted upon by the first electric field or the second electric field and, depending thereon, influences the polarization state of light passing through it
Implementation Method 2
Each of the layers comprises a material with a plurality of light-absorbing transition dipole moments. At least in a first state, each transition dipole moment is oriented, with a tolerance of 10° at the maximum, parallel to a first preferential direction selectable for the first optical element
Implementation Method 3
Light which is incident in the first optical element is transmitted or at least partially absorbed depending on its incident direction relative to the layers and depending on its polarization state
Data Source
AI summary
An optical element which can be utilized in various versions and implementations of switchable light filters having, in addition, polarization filters and/or other means for varying the polarization characteristics of light, for example, liquid crystal layers. A combination of switchable light filter and imaging display device makes possible a private viewing effect that can be switched on and off. The optical element comprises a first layer or a first layer and a plurality of further layers, each layer including a material with a plurality of light-absorbing transition dipole moments. At least in a first state, each transition dipole moment is oriented, with a tolerance of 10° at the maximum, parallel to a selectable preferential direction or fluctuates around it so that light which is incident in the optical element is transmitted or at least partially absorbed depending on its incident direction.