Optical Waveguide Element with Controllable Reflector Array for Backlight Modules
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Solution Overview
Problem
In HDR backlight modules, the wide emission range of LEDs leads to mutual crosstalk between adjacent sections, reducing the collimation degree of light and affecting display quality.
Innovation Solution
An optical waveguide element with a controllable reflector array is introduced, allowing light to be either reflected out or continue being totally reflected, increasing the collimation degree of emitted light and reducing crosstalk by adjusting the deflection angle of reflectors within the array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a wide emission range LED is used to provide light source, then the illumination intensity and coverage area are improved, but the collimation degree of light deteriorates and mutual crosstalk between adjacent sections occurs
Solution Approach 1:
The patent segments the optical waveguide into multiple independent sections, each with its own reflector array that can be independently controlled. This segmentation allows each section to manage its light emission separately, preventing mutual crosstalk while maintaining high illumination intensity across the entire display area.
Solution Approach 2:
The patent employs dynamically controllable reflectors (such as liquid crystal or electrochromic materials) that can change their optical properties in real-time. These dynamic reflectors adjust the collimation degree and emission direction of light based on control signals, enabling precise light management to eliminate crosstalk while preserving high brightness.
2Manufacturing precision
If the reflector array is made controllable to adjust deflection angle, then the collimation degree and reduction of crosstalk are improved, but the device complexity increases
Solution Approach 1:
The patent uses universal control circuits and driving mechanisms that can manage multiple reflectors across different sections using the same control architecture. This multi-functional approach allows a single control system to adjust deflection angles of numerous reflectors simultaneously, reducing overall system complexity while achieving precise light collimation and crosstalk elimination.
Solution Approach 2:
The patent replaces complex mechanical reflector adjustment mechanisms with field-effect control methods (such as electric fields in liquid crystals or electromagnetic fields in electrochromic materials). This substitution eliminates the need for physical moving parts, reducing mechanical complexity while maintaining precise control over reflector deflection angles for optimal light collimation.
3Volume of moving object
If the reflector is positioned closer to the light incident surface, then the structural compactness is improved, but the light undergoes fewer total reflections and the control precision deteriorates
Solution Approach 1:
The patent positions reflectors at optimized locations within the optical waveguide and uses multi-dimensional light reflection paths (including side walls and bottom surfaces) to achieve sufficient total internal reflections. This spatial optimization allows compact waveguide dimensions while maintaining precise light control through strategically placed reflectors that intercept light after adequate reflections.
Solution Approach 2:
The patent optimizes the refractive index parameters of the waveguide materials and adjusts the incident angle parameters of incoming light to ensure that light undergoes sufficient total internal reflections before reaching the reflectors. By changing these optical parameters, the system achieves precise light control even with compact waveguide dimensions and reflector positioning.
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 effectively increases the collimation degree of light emitted from the optical waveguide element, reducing crosstalk between adjacent sections and enhancing display quality, making it suitable for anti-peep and directional backlight modules.
Implementation Method 1
a light entering the cavity from the light incident surface is configured to propagate and be totally reflected in the cavity
Implementation Method 2
a reflector array, located in the cavity and configured to be controllable to cause at least a part of the light incident on the reflector array to be reflected out of the light emergent surface
Data Source
AI summary
An optical waveguide element and control method thereof, a backlight module and a display device. The optical waveguide element includes a cavity, a light incident surface and a light emergent surface, light entering the cavity from the light incident surface is configured to propagate and be totally reflected in the cavity; and a reflector array, located in the cavity and configured to be controllable to cause at least a part of the light incident on the reflector array to be reflected out of the light emergent surface or to continue being totally reflected at the light emergent surface.