Switchable Directional Illumination Using Micro-LEDs and Catadioptric Optics
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Solution Overview
Problem
Existing display technologies face challenges in providing switchable directional light output distributions with high efficiency and resolution, as micro-louver films are inefficient and limit light output, and current backlights have fixed directional distributions that cannot be easily adjusted.
Innovation Solution
An illumination apparatus comprising an array of micro-LEDs and catadioptric optical elements, where the LEDs are independently controllable to provide two different directional light output distributions, using a combination of refraction and reflection to direct light into smaller or larger solid angles, allowing for efficient switching between wide and narrow angle modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If micro-louver films are added to achieve narrow directional light output distribution, then privacy viewing and night time display are improved, but light efficiency significantly deteriorates due to light absorption
Solution Approach 1:
The patent replaces the mechanical micro-louver film structure with a controllable optical system using liquid crystal elements and diffusers. Instead of using fixed physical structures that absorb light, the system uses controllable optical properties of liquid crystals to achieve directional light distribution without significant light loss.
Solution Approach 2:
The patent introduces a dynamic switching mechanism between wide directional and narrow directional light output distributions. The liquid crystal elements can be controlled to change their optical state, allowing the display to switch between different viewing angle modes (wide for sharing, narrow for privacy/night time) without physical reconfiguration.
2Manufacturing precision
If fixed layers such as prismatic films and diffusers are added to alter directional light output distribution, then viewing angle control is improved, but adaptability deteriorates because the distribution is fixed by design at manufacture
Solution Approach 1:
The patent replaces fixed optical layers with a dynamic liquid crystal-based optical system. The liquid crystal elements can be electrically controlled to change their orientation and optical properties, enabling the display to switch between wide and narrow directional light output distributions after manufacture, providing adaptability while maintaining precise viewing angle control.
Solution Approach 2:
The patent changes the optical parameters (refractive index, orientation) of the liquid crystal elements through electrical control to achieve different directional light distributions. By adjusting the liquid crystal molecule orientation, the system can dynamically alter the light output distribution without changing the physical structure of the display.
3Use of energy by moving object
If inorganic LEDs are used to achieve high luminous efficiency and high luminous emittance, then power consumption is reduced, but device complexity increases due to precise alignment requirements with optical elements
Solution Approach 1:
The patent merges the LED array with the liquid crystal optical elements into an integrated structure. The diffusers and liquid crystal elements are positioned and configured to work in conjunction with the LED array, creating a unified system where the optical components are inherently aligned with the light sources, reducing the need for separate alignment procedures.
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 a thin, efficient, and compact directional illumination system that can be switched between different light output distributions, reducing power consumption, increasing luminance, and providing privacy operation while maintaining uniformity and high resolution.
Implementation Method 1
using a combination of refraction and reflection to direct light into smaller or larger solid angles
Implementation Method 2
using a combination of refraction and reflection to direct light into smaller or larger solid angles
Data Source
AI summary
A switchable directional illumination apparatus comprises first and second arrays of LEDs, some of which are micro-LEDs; an aligned catadioptric micro-optic array and an aligned light guide array. In a first mode a narrow angular output is provided by a first micro-LED array and catadioptric micro-optics. In a second mode a wider angular output is provided by the second LED array and light guides. A thin and efficient illumination apparatus may be used for switching illumination in environmental lighting, display backlighting or direct display.