US 5949347

Patent Overview — US 5,949,347 A

Title: Light emitting diode retrofitting lamps for illuminated signs

Assignee/Applicant of record (per supplied text): Original assignee Leotek Electronics Corp; later current assignees listed as Leotek Electronics Corp and Leotek Electronics USA Corp.

Key dates: Priority date 1996-09-11; application no. US08/914,967; filing date 1997-08-20; granted/publication date 1999-09-07; anticipated expiration 2017-08-20; status "Expired - Lifetime."

Purpose: The patent addresses illumination in signs such as "EXIT" signs, which conventionally use incandescent or fluorescent lamps threaded into internally mounted sockets. The stated problem is that existing LED retrofit lamps do not provide sufficiently bright, uniform illumination of the translucent signage. The invention is an LED retrofit lamp that inserts directly into the existing lamp socket, so a sign can be converted without replacing its lamp sockets.

Plain-language scope (as described in the excerpt):

• An LED lamp has a lamp base, an elongated lamp frame with a longitudinal axis and a front face, and first and second linear arrays of LEDs mounted on the front face, extending substantially parallel to the longitudinal axis.
• The frame forms a U-shaped front face; the two linear arrays are mounted to "partially face toward or partially face away from" each other. Some LEDs are adjusted upward, others downward.
• This partially opposing arrangement is said to evenly and brightly illuminate a portion of an adjacent sign face that is significantly wider and/or longer than the lamp itself.
• The disclosed illuminated-sign aspect includes a housing with a front display panel having translucent indicia, plus the LED lamp positioned adjacent the panel; the arrays project most of their light onto the panel at non-perpendicular angles.
• The excerpt references U.S. Pat. Nos. 5,388,357 and 5,459,955 as earlier LED sign approaches, describing non-uniform illumination.

Source: https://patents.google.com/patent/US5949347/en

What the excerpt does not establish: It does not give the full claim text, the full specification, dependent-claim details, or the complete drawing descriptions. It does not establish prosecution history, actual claim interpretation, scope of any continuing applications, or current ownership beyond the listed assignees. Consistent with the requested scope, no litigation, transfer, validity, or prior-art analysis is offered here.