Reflective LCD Light Guide Panel with Directive Reflector
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Solution Overview
Problem
Liquid crystal displays (LCDs) face challenges in low light conditions, where reflective modes struggle to provide visibility, and in bright light conditions, transmissive displays become washed out due to overpowering ambient illumination, with current transflective solutions compromising on reflectivity and power efficiency.
Innovation Solution
Incorporating a light guide panel with light sources and a directive reflector to distribute light effectively across a reflective LCD, varying illumination based on ambient light levels, and using a directive reflector to improve overall reflectivity by avoiding optically disruptive display components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If reflective mode is used in low light conditions, then power consumption is reduced, but visibility deteriorates
Solution Approach 1:
The display system is segmented into two operational modes: reflective mode for low light conditions (power saving) and transmissive mode for bright light conditions (visibility). The control system automatically switches between modes based on ambient light detection, allowing the display to optimize between power consumption and visibility for each condition independently
Solution Approach 2:
The display dynamically adapts its illumination characteristics by switching between reflective and transmissive modes based on ambient light conditions. This dynamic adaptation allows the display to maintain optimal visibility across varying lighting environments while minimizing power consumption in low light conditions
2Illumination intensity
If transmissive mode is used in bright light conditions, then visibility is improved, but image quality deteriorates due to washed out appearance
Solution Approach 1:
The display system segments its operation into reflective mode for bright light conditions (maintaining image quality) and transmissive mode for low light conditions (ensuring visibility). By detecting ambient light levels, the system switches to reflective mode in bright conditions, preventing the washed out appearance while maintaining good visibility through the inherently higher contrast of reflective displays
3Adaptability or versatility
If transflective mode is used, then adaptability to different lighting conditions is improved, but reflectivity and power efficiency deteriorate
Solution Approach 1:
Rather than using a single transflective mode that compromises both reflectivity and power efficiency, the system segments operation into distinct reflective and transmissive modes. This allows each mode to be optimized for its specific condition: reflective mode maximizes power efficiency and reflectivity in bright conditions, while transmissive mode ensures visibility in low light, avoiding the inherent compromises of transflective technology
Solution Approach 2:
The system changes its optical parameters dynamically by switching between reflective and transmissive modes. In reflective mode, the display utilizes ambient light reflection with minimal power consumption. In transmissive mode, active illumination is provided when needed. This parameter change approach maintains high reflectivity and power efficiency in appropriate conditions while ensuring visibility when required
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
Enhances visibility in low light conditions while maintaining image quality in bright light without excessive power consumption, by optimizing light distribution and reflectivity, thus improving user experience and display performance.
Implementation Method 1
The light guide panel comprises one or more materials configured to direct light along a planar surface
Implementation Method 2
a directive reflector to improve overall reflectivity by avoiding optically disruptive display components
Data Source
AI summary
Devices such as electronic book readers, tablet computers, laptops, and so forth may use reflective liquid crystal display (“LCD”) technologies. Described herein are devices and methods for illuminating the reflective LCD with a light guide panel. The light guide panel is configured with diffractive or other optical features configured to distribute light to the reflective LCD. A directive reflector may be arranged behind the reflective LCD to improve overall reflectivity by directing impinging light such that optical obstructions such as transistors and electrical traces within the reflective LCD are avoided.