US 7815338

Patent Overview — US 7,815,338 B2

Title: "LED lighting unit including elongated heat sink and elongated lens"

Source: https://patents.google.com/patent/US7815338/en

Identifying data (from supplied text): Publication number US7815338B2; application US12/040,901; inventors Dennis Siemiet, David L. Simon, and Huaiyao Yuan; original assignee Altair Engineering Inc.; current assignee listed as Ilumisys Inc.; priority/filing date 2008-03-02; publication date 2010-10-19; status "Active, expires 2028-10-13."

Purpose. The invention relates to an LED housing including a lens and a heat sink that retains the lens. LED lighting units generally include LEDs mounted on a heat sink and enclosed by a lens; the lens protects the LEDs and circuitry and may provide optical characteristics such as light diffusion. The stated aim is a heat sink and lens forming a housing that is less expensive to manufacture than known LED housings, has improved thermal conductivity, and can accept less expensive diffusing means. In one described arrangement, the LED light tube is configured to replace a conventional fluorescent light tube in a conventional fluorescent light socket.

Plain-language scope. An elongated heat sink has two spaced-apart longitudinal grooves. Groove orientation varies: tangentially facing, facing at an angle relative to a radius at the groove, or facing in opposing directions. At least one LED is mounted to the heat sink between the grooves and enclosed by a lens having bulged longitudinal edges; the lens attaches by sliding those bulged edges into the grooves. In one form the grooves have cross-sections including a circular portion, and the heat sink has a constant cross-section, a flat strip running its length, and fins on the opposing side from the flat strip. LEDs are in electrical communication with a printed circuit board mounted on the flat strip. An elongated substantially U-shaped lens of constant cross-section has bulged edges of circular cross-section and a bend shortly before each bulged edge. A rectangular sheet of diffusing film is inserted between heat sink and lens, and at least one bi-pin electrical connector connects to an end of the housing.

What the excerpt does not establish. It does not provide the full claim set, the complete written description, the exact wording of claim limitations, the drawing reference numerals beyond those named, or any finding on validity, infringement, ownership transfers, or prior art. It also does not explain the truncated angle discussion (the text cuts off mid-sentence regarding angle θ). The excerpt notes the patent family had litigation, but no outcome is shown.