Luminaire Reflective Screen Glare Reduction
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Solution Overview
Problem
Traditional LED-based luminaires face challenges in distributing concentrated brightness evenly for indirect illumination, leading to glare issues due to excessive contrast and direct light emission through specularly reflective parts, which do not comply with glare restrictions and result in visible light source images.
Innovation Solution
The luminaire incorporates shielding means with a concavely shaped specularly reflective part that directs light towards a diffusely reflective part, ensuring all light reaching the exit window is reflected diffusely, minimizing glare and maximizing optical efficiency by controlling light distribution and reducing the risk of light redirection to the source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a specularly reflective part is used to reflect light towards the exit window, then light distribution efficiency is improved, but visible light source images remain and increase glare risk
Solution Approach 1:
The reflective screen is segmented into two distinct parts: a specularly reflective part for efficient light reflection and a diffusely reflective part for glare reduction. This segmentation allows each part to perform its specific function optimally without the drawbacks of the other.
Solution Approach 2:
Different regions of the reflective screen have different reflective properties. The specularly reflective part uses mirror-like reflection for efficiency, while the diffusely reflective part uses diffuse reflection to scatter light and eliminate visible source images, creating local quality variations to solve the contradiction.
2Use of energy by moving object
If LEDs are used as light sources, then energy efficiency is improved, but concentrated brightness is difficult to distribute evenly
Solution Approach 1:
The reflective screen acts as an intermediary between the concentrated LED light source and the exit window. It redistributes the concentrated brightness through reflection, transforming it into uniform illumination that maintains energy efficiency while solving the uniformity problem.
Solution Approach 2:
The invention transforms the point-source concentrated light into a distributed surface illumination by using the reflective screen to redirect light across multiple dimensions, achieving even distribution across the exit window area.
3Object-affected harmful factors
If shielding means are added to block direct light from contacting means, then glare is reduced, but device complexity increases
Solution Approach 1:
The shielding function is merged with the reflective screen structure. The reflective screen serves dual purposes: reflecting light towards the exit window and simultaneously shielding the contacting means from direct observation, reducing complexity by combining functions.
Solution Approach 2:
The reflective screen is designed to perform multiple functions: light reflection, glare reduction, and shielding of contacting means. This multi-functionality eliminates the need for separate shielding components, maintaining simplicity while achieving glare reduction.
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 design achieves uniform illumination, minimizes glare, and increases optical efficiency by ensuring most light is reflected diffusely, reducing the luminaire's height and preventing visible light source images, thus enhancing user comfort and performance.
Implementation Method 1
a reflective screen opposite the light exit window comprising both a specularly reflective part adjacent the light sources and a diffusely reflective part opposite the light exit window
Implementation Method 2
a diffusely reflective part opposite the light exit window... light is still emitted through the light exit window directly by the specularly reflective part of the reflective screen, i.e. not via its diffusely reflective part
Data Source
Figure 1A~1B
Figure 1C
Figure 2
AI summary
The invention relates to a luminaire (2) and an illumination system (12). The luminaire according to the invention comprises a light exit window (30) for emitting light from the luminaire, and a reflective screen (40) arranged opposite the light exit window. The luminaire further comprises a light source (20) which is arranged for indirect illumination of the light exit window via the reflective screen. The light source is arranged near the light exit window on an imaginary plane P substantially parallel to the light exit window and emits light away from the light exit window. The luminaire further comprises a specularly reflective part (43) as part of the reflective screen, which specularly reflective part is concavely shaped for reflecting at least part of the light emitted by the light source towards a diffusely reflective part (42) of the reflective screen. The luminaire according to the invention has the effect that use of the specularly reflective part allows an improved controlled reflection of the portion of the light emitted by the light source towards the diffusely reflective part.