The GE Limelight night light package notes that it is covered by US patent 5,662,408, “Simple plug in night light having a low profile”. I was suprised to discover that this patent doesn’t cover the lamp’s technology: electroluminescence. Rather, the novelty is that its design is simple to manufacture, and thus cheap.
The patent abstract is so simple that it’s worth quoting in full: “The night light has a case with a front side and a rear side. The front side of the case has a portion defining a window. The lamp is secured between the sides and covering the window. The lamp has conductors for connecting to an electrical supply which are in electrical contact with a first and second blade, the blades extending from the rear exterior face of the case for engaging an electrical outlet. The blades are held in a slot through the rear side of the case and by a portion of the blades which engages the interior face of the front side of the case.”
The inventor, Joseph Marischen, has four other patents to his credit. Three are for other night light designs, and one is for an Animal training method using positive and negative audio stimuli.
Overall, there is no shortage of filings in the technology area: a search on the USPTO database gives 1655 hits for patents with “electroluminescent” in their title.
