Elongated LED Lamp with Optical Waveguide for Fluorescent Replacement
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Solution Overview
Problem
Elongated fluorescent lamps have poor color rendering and aesthetics due to their wavelength distribution, and LED-based replacements often suffer from glare and high costs when trying to maintain light output and color quality.
Innovation Solution
An elongated LED lamp design featuring a chassis with a power regulating circuit, light-collection means, and a side-light distribution arrangement that uses a rod-shaped structure with light-extraction means to distribute light evenly and reduce glare, while being securely held in place by a bracket system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a large array of LEDs (100 or more) is used to replace a fluorescent tube, then the light output can be maintained, but the device cost increases and glare spots are created
Solution Approach 1:
The patent introduces an optical waveguide as an intermediary component between the LED light source and the illumination space. The waveguide receives light from a single LED and distributes it along its length through total internal reflection, with light extraction surfaces providing uniform illumination. This mediator allows one LED to replace what would otherwise require many LEDs, eliminating glare spots while maintaining light output and reducing device complexity.
2Device complexity
If the number of LEDs is reduced to decrease device complexity, then cost is reduced, but maintaining the same light output becomes difficult
Solution Approach 1:
The patent transitions from point-source illumination (direct LED emission) to distributed linear illumination by introducing the waveguide dimension. The waveguide extends the light distribution in the longitudinal dimension, allowing a single LED's light to be spread over a longer distance. This dimensional transformation enables one LED to provide the same total light output that would otherwise require many LEDs arranged in an array.
Solution Approach 2:
The optical waveguide acts as an intermediary that couples the single LED source to the illumination space, efficiently transporting and distributing light along the waveguide length through total internal reflection and controlled extraction at light extraction surfaces.
3Device complexity
If LED brightness is increased to maintain light output with fewer LEDs, then device complexity is reduced, but glare spots are exacerbated
Solution Approach 1:
The waveguide serves as an intermediary that diffuses the light from the bright LED source along its length. By distributing the light over an extended surface area through the light extraction surfaces, the waveguide converts the concentrated bright source into uniform ambient illumination, eliminating glare spots while allowing the use of fewer, brighter LEDs.
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 LED lamp provides a pleasing color distribution without glare spots and effectively replaces fluorescent lamps, maintaining light output while reducing costs through efficient light distribution and heat management.
Implementation Method 1
a first light-collection means has an inlet end that collects at least 25 percent of the light emitted by the first light source, and has an outlet end that directs over half of the light collected at the inlet end with an angular distribution different from that of the light when received at the inlet end
Implementation Method 2
The first portion comprises a rod with an elongated shape having a minimum cross-sectional dimension along a length of the first portion that exceeds 50 percent of the maximum cross-sectional dimension along such length. Light-extraction means extract light from the side of the first portion, along a length of the first portion, in a different direction from the direction of light received from the first light-collection means
Data Source
AI summary
An elongated LED lamp suitable for replacing a fluorescent lamp in a lamp fixture comprises a chassis having a first chassis end with two electrodes adapted to be respectively coupled to two electrodes in the lamp fixture supplying AC power, and a second chassis end. A light source depends from the chassis. A power regulating circuit is mounted to the chassis and is coupled to the two electrodes for providing DC power to the first light source. A first light collector conditions the light it collects light from the first light source for TIR propagation within a side-light distribution arrangement. An elongated side-light distribution portion depends from the chassis and receives light exiting the first light collector. Light-extraction structure extract light from the side of the first portion, along a length of the first portion, in a different direction from the direction of light received from the first light collector.