Patent No. USRE48489 (titled "Gas Cooled Led Lamp") was filed by Fgi Worldwide Llc on Feb 26, 2018.
’489 is related to the field of solid-state lighting , specifically LED lamps designed as replacements for traditional incandescent or fluorescent bulbs. These LED lamps aim to offer advantages such as lower energy consumption, longer lifespan, and improved durability. A key challenge in designing these lamps is managing the heat generated by the LEDs and power supply within a compact, self-contained structure.
The underlying idea behind ’489 is to use a gas-filled enclosure to provide efficient thermal coupling between the LED array and the lamp's outer enclosure. This approach allows for effective heat dissipation without relying on direct physical contact between the LED array and a traditional heat sink, which can obstruct light output and limit LED placement. The gas acts as a thermally conductive medium , transferring heat from the LEDs to the enclosure, which then dissipates the heat to the surrounding environment.
The claims of ’489 focus on a lamp comprising an optically transmissive enclosure connected to a base, an LED array operable to emit light when energized through an electrical connection, a gas contained in the enclosure to provide thermal coupling to the LED array, and a heat sink structure thermally coupled to the LED array for transmitting heat from the LED array to the enclosure primarily through the gas. The heat sink structure is positioned entirely inside of the enclosure and is spaced from the base such that the heat sink structure is supported in the interior space at a distance from the enclosure of less than 8 mm.
In practice, the LED array is mounted on a submount, which may include a heat sink structure with fins to increase the surface area for heat transfer. The enclosure is filled with a gas, such as helium or a mixture of helium and oxygen, which facilitates the transfer of heat from the LED array to the enclosure walls. A gas movement device, like a small fan, may be included to further enhance heat transfer by circulating the gas within the enclosure.
This design differs from prior approaches that rely on direct physical contact between the LED array and a heat sink, which can create shadows and limit the lamp's light distribution. By using a gas-filled enclosure, ’489 enables a more uniform light pattern and allows for greater flexibility in LED placement. The inclusion of oxygen in the gas mixture also addresses the issue of LED degradation in sealed environments, ensuring a longer lifespan for the lamp.
In the early 2010s when ’489 was filed, LED lighting was becoming a more viable alternative to traditional incandescent and fluorescent lighting, at a time when thermal management within LED lamps was typically implemented using heat sinks and other passive cooling methods. At that time, the design of LED lamps as replacements for standard bulbs presented challenges because the power supply and heat sink could obstruct light or limit LED placement.
The examiner allowed the claims because the prior art did not disclose or make obvious a heat sink positioned entirely inside the enclosure and spaced from the base, supported in the interior space at a distance less than 8mm from the enclosure. The examiner also stated that the prior art failed to disclose or render obvious the inclusion of the limitation "a gas movement device".
This patent contains 35 claims, with independent claims numbered 1, 10, 11, and 19. The independent claims generally focus on a lamp comprising an optically transmissive enclosure, an LED array, a gas for thermal coupling, and a heat sink structure. The dependent claims elaborate on specific features, configurations, and compositions of the lamp components described in the independent claims.
Definitions of key terms used in the patent claims.

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