Expandable Light Guide With Sliding LED Subassembly
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Solution Overview
Problem
Thermal expansion and contraction of light guides in backlit displays cause mechanical and optical defects, as existing solutions fail to maintain the optimal distance between LEDs and light guides across varying temperatures.
Innovation Solution
Incorporating a sliding LED subassembly connected to the light guide, with slots allowing the light guide to expand and contract while maintaining the distance between LEDs and the light guide, using a post system that moves with the light guide to prevent distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the light guide is made rigid to maintain structural stability, then mechanical strength is improved, but thermal expansion/contraction causes mechanical and optical defects
Solution Approach 1:
The patent applies the dynamics principle by making the light guide movable relative to the LED assembly through a slot-based mechanism. The light guide can expand and contract thermally while moving within the slots, maintaining optimal optical alignment. This transforms the rigid structure into a dynamic system that adapts to thermal changes, resolving the contradiction between mechanical strength and optical reliability.
Solution Approach 2:
The patent changes the positional parameter of the light guide relative to the LED assembly by allowing movement along the slots. This parameter change enables the light guide to accommodate thermal expansion and contraction while maintaining proper optical alignment, thus preserving optical performance despite temperature variations.
2Stress or pressure
If the light guide is allowed to expand and contract freely, then thermal stress is reduced, but the distance between LEDs and light guide changes causing optical defects
Solution Approach 1:
The slots act as an intermediary mechanism between the LED assembly and the light guide. They allow controlled movement that accommodates thermal expansion while constraining the motion to maintain proper spacing. The slots mediate between free expansion (stress relief) and fixed positioning (precision maintenance), enabling both objectives to be achieved simultaneously.
Solution Approach 2:
The dynamic connection through slots allows the light guide to move in response to thermal changes while maintaining optimal distance from the LEDs. This dynamic adjustment prevents both excessive thermal stress accumulation and precision loss, resolving the contradiction between stress reduction and precision maintenance.
3Manufacturing precision
If fixed mounting is used to maintain precise LED-to-light guide distance, then optical alignment is improved, but thermal expansion causes mechanical defects
Solution Approach 1:
The patent replaces fixed mounting with a dynamic slot-based connection that allows the light guide to move with thermal expansion while maintaining alignment. The slots provide guided movement that preserves optical precision while accommodating dimensional changes, thus maintaining mechanical integrity under thermal stress.
Solution Approach 2:
The patent allows the positional parameter of the light guide to change within the constraints of the slots. This controlled parameter change enables thermal expansion without compromising alignment precision, as the movement is constrained to maintain proper optical geometry while relieving mechanical stress.
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
This solution effectively prevents mechanical and optical defects by allowing the light guide to expand and contract without altering the critical distance between LEDs and the light guide, ensuring consistent illumination across temperature changes.
Implementation Method 1
Thermal expansion or contraction of the light guide can cause both mechanical and optical defects in the display
Implementation Method 2
Thermal expansion or contraction of the light guide can cause both mechanical and optical defects in the display
Data Source
AI summary
Described herein are exemplary embodiments of a light guide assembly for a backlight and backlight assemblies using such light guide assemblies. An exemplary backlight assembly may have a light guide with a pair of opposing edges and a sliding LED subassembly placed along an edge of the light guide and attached to the light guide so that movement of the light guide causes movement of the sliding LED subassembly. In some embodiments, a first slot may be positioned within the light guide where a post extends from the sliding LED subassembly to engage with the first slot in the light guide. In some embodiments, a back pan may be positioned behind the light guide where a post can extend from the back pan to engage with a second slot in the light guide.