Downlight Fixture Uniform Illumination via Indirect Reflection
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Solution Overview
Problem
Conventional downlight fixtures with backlit illumination suffer from non-uniform brightness and glare due to high contrast between light sources and non-light emitting areas, leading to undesirable visual hot spots, and existing solutions that address this issue either diminish light output efficiency or result in an unsightly thick profile.
Innovation Solution
A downlight fixture design featuring a housing reflector member with a curved and stairway-shaped portion, a top reflector panel, and strategically positioned LEDs outside the lens perimeter, which directs light towards a luminous cavity to increase indirect illumination, reducing direct light exit and maintaining a thin profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the thickness of the downlight fixture is increased to provide a larger distance between the light sources and the lens, then the uniformity of illumination is improved, but the light output efficiency is diminished
Solution Approach 1:
The patent positions light sources in a third dimension above the lens plane rather than directly behind it. The light sources are disposed on a surface of the top reflector panel facing the lens and adjacent to a perimeter of the top reflector panel, placing them outside a perimeter of the lens. This spatial reconfiguration allows uniform illumination without requiring increased thickness.
2Illumination intensity
If a very thick diffusing lens is used to reduce contrast between light sources and surrounding areas, then the uniformity of illumination is improved, but the profile thickness becomes undesirable
Solution Approach 1:
Instead of using a thick lens to achieve uniformity, the patent uses a three-dimensional arrangement of light sources positioned above and outside the lens perimeter. The reflector panel and housing reflector member create a luminous cavity that distributes light uniformly without requiring increased profile thickness.
Solution Approach 2:
The patent introduces a top reflector panel and housing reflector member as intermediary elements between the light sources and the lens. These reflectors create a luminous cavity that diffuses and redirects light, achieving uniform illumination without requiring a thick lens or increased fixture thickness.
3Illumination intensity
If the distance between light sources and lens is increased to reduce visual hot spots, then the uniformity of illumination is improved, but the device complexity increases
Solution Approach 1:
The patent achieves uniformity by positioning light sources in a different spatial plane above the lens rather than increasing the distance along the optical axis. This dimensional reconfiguration reduces the need for complex thick-lens designs while maintaining uniform illumination.
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
The design achieves uniform lens illumination by minimizing direct light exit and maximizing indirect light, thereby reducing glare and maintaining a thin profile, enhancing both functionality and aesthetics.
Implementation Method 1
a housing reflector member with a curved and stairway-shaped portion, a top reflector panel, and strategically positioned LEDs outside the lens perimeter, which directs light towards a luminous cavity to increase indirect illumination
Data Source
AI summary
A downlight fixture includes a housing reflector member having a top edge that defines a first aperture, a bottom edge that defines a second aperture, and a body that extends from the top edge to the bottom edge. Further, the downlight fixture includes a top reflector panel coupled to the housing reflector member such that it covers the first aperture. Furthermore, the downlight fixture includes a lens that is coupled to the housing reflector member such that it covers the second aperture. An inner surface of the body and a surface of the top reflector member facing the lens are reflective. Additionally, the downlight fixture includes a plurality of light sources disposed on the top reflector member adjacent a perimeter of the top reflector panel such that the plurality of light sources are outside a perimeter of the lens and facing the inner surface of the housing reflector member's body.