Absorptive Reflector Lighting Assembly for Homogeneous LCD Backlighting
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Solution Overview
Problem
Lighting arrangements for display devices, such as LEDs, often suffer from inadequate homogeneous illumination due to brightly lit sub-areas causing disruptive effects, and existing solutions struggle to shape radiation according to a predetermined characteristic effectively.
Innovation Solution
A lighting arrangement featuring an optical device with a radiation exit surface and an optoelectronic component, where a reflector-like element is designed to absorb radiation generated by the semiconductor chip, primarily reducing radiation that would otherwise be reflected and emitted at difficult-to-control angles, allowing for simplified shaping of the radiation according to a predetermined emission characteristic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflector-like element is used to deflect radiation through the radiation exit surface, then radiation can be directed towards the exit surface, but radiation reflected at the element emerges at difficult-to-control angles and creates scattered radiation
Solution Approach 1:
Instead of making the reflector-like element reflective to deflect radiation, the invention inverts the approach by making the element absorbent. This absorbs the harmful scattered radiation that would otherwise be reflected at difficult-to-control angles, while allowing directly generated radiation to pass through the optical device for controlled shaping.
2Power
If radiation from the semiconductor chip is allowed to exit through side surfaces, then total radiant power is increased, but the radiation cannot be shaped according to predetermined emission characteristics
Solution Approach 1:
The invention extracts or removes the problematic side-surface radiation by using the absorbent reflector-like element to selectively absorb radiation that would otherwise exit through side surfaces. This allows the optical device to shape only the radiation from the intended surface, achieving precise emission characteristics while maintaining high total radiant power from the primary radiation path.
3Illumination intensity
If multiple reflections occur within the lighting arrangement, then radiation can be redirected towards the radiation exit surface, but the radiation angles become difficult to control and homogeneity is reduced
Solution Approach 1:
The invention converts the harmful effect of multiple reflections (which create scattered radiation and reduce homogeneity) into a benefit by using the absorbent reflector-like element to selectively absorb these reflected rays. This eliminates the disruptive scattered radiation while preserving the beneficial directly generated radiation, achieving improved illumination homogeneity without requiring complex radiation path control.
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 enhances the homogeneity of illumination by reducing scattered radiation, improving the control over the radiation pattern, and increasing the radiant power emitted, particularly suitable for backlighting display devices like LCDs, while minimizing the impact of phantom light and enhancing contrast ratios.
Implementation Method 1
an optoelectronic component with at least one semiconductor chip (5) provided for generating radiation
Implementation Method 2
the element shaped like a reflector is designed to absorb radiation generated in the optoelectronic component in a targeted manner
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5B
AI summary
A lighting assembly (1) is disclosed which includes an optical device (4) with a radiation output surface (41) and an optoelectronic component (2) for the production of radiation, wherein a reflector-shaped element (3) is formed. The reflector-shaped element (3) has a shape and arrangement suitable to return the radiation (70) produced in the component (2) through the radiation output surface (41), and is intentionally constructed for the absorption of this radiation (70). The lighting assembly preferably provides a particularly homogeneous backlighting of indicators such as liquid crystal displays (LCDs).