Laser Backlight Beam Shaping for Uniform Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current backlighting technologies for flat panel displays, such as LCDs, face inefficiencies due to the broad spectrum of fluorescent lamps requiring complex filtering, leading to wasted light and undesirable heating, while laser-based solutions need new light shaping techniques for uniform illumination without wasting light.
Innovation Solution
A surface light emitting apparatus using a light source section with a laser beam, an optical guiding section, and a beam shaping optical element with a powered surface to convert the Gaussian intensity distribution of the laser beam into a uniform intensity distribution, ensuring efficient and uniform illumination of the backlight panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If laser beam is used for backlighting, then energy efficiency is improved, but uniform illumination is difficult to achieve
Solution Approach 1:
The patent applies local quality by varying the refractive index or surface curvature at different locations of the optical element to compensate for the Gaussian intensity profile. The optical element is designed with spatially varying properties that redirect light from high-intensity regions to low-intensity regions, achieving uniform illumination across the backlight panel while maintaining laser energy efficiency.
Solution Approach 2:
The patent changes optical parameters such as refractive index, surface curvature, or thickness of the optical element to transform the Gaussian intensity distribution into a uniform distribution. By adjusting these parameters across different zones of the optical element, the system achieves both energy efficiency (using laser) and uniform illumination.
2Illumination intensity
If light guide is used to illuminate back panel, then uniform illumination can be achieved, but design complexity increases
Solution Approach 1:
The patent extracts the light shaping function from a complex light guide system and concentrates it into a single optical element positioned at the laser output. This optical element performs both beam shaping and uniformity correction in one component, eliminating the need for complex light guide designs with carefully controlled leakage points, thus reducing design complexity while maintaining uniform illumination.
Solution Approach 2:
The optical element serves multiple functions simultaneously: it shapes the laser beam, corrects the intensity distribution, and provides uniform illumination to the backlight panel. This multi-functionality reduces the overall system complexity compared to separate components for each function.
3Illumination intensity
If broadband emitter is used for backlighting, then high brightness is achieved, but light wastage increases
Solution Approach 1:
The patent uses laser emitters with narrow spectral linewidths centered at specific wavelengths, changing the spectral parameter from broadband to narrowband. This eliminates the need for filtering, allowing nearly 100% of the generated light to be utilized for illumination, thus achieving high brightness without light wastage.
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 achieves efficient and uniform illumination of the backlight panel, reducing light wastage and simplifying design complexity, suitable for both small and large displays, while maintaining high energy efficiency and environmental friendliness.
Implementation Method 1
an optical element section that includes at least one beam shaping optical element with a powered surface which converts an intensity distribution of the laser beam emitted from the light source section
Data Source
AI summary
A surface light emitting apparatus capable of providing uniform illumination while efficiently using a laser light. The apparatus comprises a light source section that includes at least one light source which emits laser beam; an optical guiding section that guides from an incidence surface of the optical guiding section the laser beam emitted from the light source section and emits the laser beam from a radiation surface of the optical guiding section; and an optical element section that includes at least one beam shaping optical element with a powered surface which converts an intensity distribution of the laser beam emitted from the light source section at the incidence surface of the optical guiding section to a uniform intensity distribution.