Micro LED Lens Alignment for Sidewall Light Collimation
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Solution Overview
Problem
Micro LED projectors face inefficiencies due to light loss from the sidewall of the mesa structure, as the chief ray angle is fixed vertically, leading to reduced light emission and uniformity in arrays.
Innovation Solution
A micro LED projector design incorporating a micro lens and collimator unit to control the chief ray angle and collimate light to a preset objective, with deviations and specific alignments to enhance light emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the micro LED structure uses conventional mesa design with vertical chief ray emission, then the manufacturing process is simple, but the light emitting efficiency is reduced due to large emitting angle from sidewall
Solution Approach 1:
The patent changes the chief ray angle parameter from vertical (0 degrees) to inclined angles (10-45 degrees) by adjusting the micro lens position relative to the mesa structure. This parameter change redirects the chief ray to emit at an angle, allowing sidewall-emitted light to be utilized effectively, thereby improving light emitting efficiency without complicating the manufacturing process
Solution Approach 2:
The patent introduces a horizontal dimension to the chief ray emission by offsetting the micro lens from the mesa center along the x-axis. Instead of purely vertical emission, the light is now emitted at an angle in the horizontal plane, creating a new emission dimension that captures previously lost sidewall light
2Device complexity
If the micro LED array uses fixed vertical chief ray angle, then the structure is simple, but the application versatility is limited
Solution Approach 1:
The patent makes the chief ray angle adjustable and variable by allowing different micro lenses to be positioned at different horizontal offsets from their respective mesa centers. This creates a dynamic system where the emission angle can be customized for each micro LED or group of micro LEDs, enabling diverse applications such as augmented reality displays, virtual reality headsets, and projection systems with different optical requirements
Solution Approach 2:
The patent applies different chief ray angles to different regions or individual micro LEDs within the array. By locally adjusting the micro lens position for each mesa structure, each micro LED can be optimized for its specific function or position in the array, providing local customization of emission characteristics while maintaining overall array functionality
3Volume of stationary object
If the micro LED projector uses conventional design without chief ray angle control, then the device volume is smaller, but the light distribution is inefficient
Solution Approach 1:
The patent integrates the micro lens directly onto the mesa structure with the micro LED, forming a nested configuration where the lens is positioned immediately above the light emitting region. This nesting eliminates the need for separate, bulky optical components and allows precise control of the chief ray angle within a compact footprint, maintaining small projector volume while improving light distribution efficiency
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 reduces light loss and enhances light emission intensity and uniformity across the micro LED array, improving overall projector performance.
Implementation Method 1
a micro lens formed to be above the micro mesa structure
Implementation Method 2
a collimator unit, formed to collimate rays emitted from the micro LED structure to a preset objective position
Data Source
AI summary
Disclosed herein is a micro LED projector comprising: a micro LED panel and a collimator unit. The micro LED structure in the micro LED panel comprises a mesa structure and a micro lens formed above the micro mesa structure, a p type semiconductor layer, an n type semiconductor layer and a light emitting layer formed between the p type semiconductor layer and the n type semiconductor layer. The center of the micro lens is at a straight line which connects the center of the light emitting layer with the center of the collimator unit. The present disclosure decreases the volume and the weight of the micro LED projector.