LED Bulb Back-Reflecting Optic for Omnidirectional Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LED lighting systems with a power supply or driver in the base often obstruct light emission in the direction of the base, hindering the achievement of an omnidirectional luminous intensity distribution, which is a requirement in some standards for solid-state lighting products.
Innovation Solution
Incorporating an optically transmissive enclosure with a total-internal-reflection (TIR) optic and a central aperture on the driver base, which down-reflects light from the LEDs, enabling an omnidirectional light distribution by directing light rays through the central aperture and diffusive areas to achieve uniform illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a power supply and electronic circuitry are included in the base of the LED lamp, then the lamp becomes self-contained and functional, but the light emission in the direction of the base is obstructed
Solution Approach 1:
The optical system is segmented into multiple functional zones: a first optic for down-reflecting light from LEDs, a second optic for transmitting light through the base, and a diffusive area for uniform distribution. This segmentation allows each component to address specific lighting requirements without interfering with others, resolving the contradiction between having electronics in the base and achieving omnidirectional light emission.
Solution Approach 2:
A diffusive area is introduced as an intermediary element between the light sources and the external environment. This diffusive area scatters and uniformly distributes light, acting as a mediator that allows light to pass through the base region while maintaining uniform illumination, thus resolving the obstruction caused by the power supply and circuitry.
2Device complexity
If electronic circuitry and power supply are placed in the base, then the lamp structure is complete, but omnidirectional luminous intensity distribution is hindered
Solution Approach 1:
Different regions of the optic are assigned different functions: the first optic handles down-reflection for upward light emission, while the second optic handles light transmission through the base for downward emission. This local differentiation of optical properties allows the base to serve dual purposes - housing electronics while also contributing to omnidirectional light distribution.
Solution Approach 2:
The optical system transitions from a single-dimensional light path to a multi-dimensional distribution pattern by incorporating both reflection (upward direction) and transmission (downward direction) mechanisms. This dimensional expansion enables omnidirectional illumination despite the presence of electronic components in the base.
3Illumination intensity
If light is directed downward through the base, then illumination is provided, but shadows and hot spots are created
Solution Approach 1:
The diffusive area is designed to automatically scatter and redistribute light without external control, using its own structural properties to eliminate shadows and hot spots. The diffusive material inherently performs the function of uniform light distribution, making the system self-regulating and eliminating the need for additional control mechanisms.
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 solution results in improved angular emission of light, achieving an omnidirectional distribution of light intensity from 75% to 125% of the average over a 0° to 135° angle, enhancing the light distribution while minimizing shadows and hot spots.
Implementation Method 1
an optic, for example, a total-internal-reflection (TIR) optic is disposed at least partially in an optical path from the plurality of LEDs to a central area of the optically transmissive enclosure to down-reflect at least some light from the plurality of LEDs
Data Source
AI summary
An LED bulb with a down-reflecting optic is disclosed. Embodiments of the present invention can provide for an omnidirectional intensity distribution in the vertical plane for a vertically oriented solid-state lamp. In example embodiments, an optically transmissive enclosure is installed on the driver base. A plurality of LEDs are mounted on a mounting surface of the driver base, and an optical arrangement is disposed at least partially in an optical path from the plurality of LEDs to a central area of the optically transmissive enclosure to down-reflect at least some light from the plurality of LEDs. The optical arrangement can include a TIR optic with a spline-driving surface to down-reflect the at least some light from the plurality of LEDs, or a substantially flat mirror. Either may include a central aperture, and the optical arrangement may include a diffuser or diffusive areas.